Bis[4′-(4-anilino)-2,2′:6′,2″-terpyridine] transition-metal complexes: Electrochemically active monomers with a range of magnetic and optical properties for assembly of metallo oligomers and macromolecules

Article abstract of DOI:10.1039/a702778h

The new ligand 4′-(4-anilino)-2,2′:6′,2″-terpyridine (L¹) and a range of its transition-metal complexes have been prepared. The crystal and molecular structures of L¹ and [CuL¹₂[PF₆]₂ have been determined. Model reactions show that L¹ and its transition-metal complexes can be functionalised with suitable organic reagents: reactions with aromatic dianhydrides give imide derivatives, reactions with acid chlorides afford amide derivatives and benzoquinone reacts with L¹ to give a quinonylanilinoterpyridine ligand, complexes of which are described, but not with the complexes of L¹. The use of L¹ and its complexes in building up multicomponent architectures has been tested. Metallo-dimers and co-ordination polymers linked by new binucleating bis(terpyridyl) ligands have been prepared by two routes: (a) first coupling two L¹ with difunctional organic reagents and then treating the new binucleating ligands with a metal source, or (b) preforming monomeric complexes of L¹ and treating these with the same difunctional organic reagents. Analytical, spectroscopic and electrochemical data are given for all complexes; the chromophoric, magnetic and electrochemical properties of the complexes vary with transition metal and terpyridyl ligand substituent.

Full text of DOI:10.1039/a702778h

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Bis[4Ј-(4-anilino)-2,2Ј:6Ј,2Љ-terpyridine]transition-metal complexes:
electrochemically active monomers with a range of magnetic and
optical properties for assembly of metallo oligomers and
macromolecules†
Gregory D. Storrier, Stephen B. Colbran* and Donald C. Craig
School of Chemistry, University of New South Wales, Sydney, NSW 2052, Australia
The new ligand 4Ј-(4-anilino)-2,2Ј:6Ј,2Љ-terpyridine (L1) and a range of its transition-metal complexes have been
prepared. The crystal and molecular structures of L1 and [CuL1 ][PF6]2 have been determined. Model reactions
2
show that L1 and its transition-metal complexes can be functionalised with suitable organic reagents: reactions
with aromatic dianhydrides give imide derivatives, reactions with acid chlorides afford amide derivatives and
benzoquinone reacts with L1 to give a quinonylanilinoterpyridine ligand, complexes of which are described, but
not with the complexes of L1. The use of L1 and its complexes in building up multicomponent architectures has
been tested. Metallo-dimers and co-ordination polymers linked by new binucleating bis(terpyridyl) ligands have
been prepared by two routes: (a) first coupling two L1 with difunctional organic reagents and then treating the new
binucleating ligands with a metal source, or (b) preforming monomeric complexes of L1 and treating these with
the same difunctional organic reagents. Analytical, spectroscopic and electrochemical data are given for all
complexes; the chromophoric, magnetic and electrochemical properties of the complexes vary with transition
metal and terpyridyl ligand substituent.
Aromatic tetracarboxylic dianhydrides and aromatic diamines
co-condense to give polyimides which exhibit desirable physical
properties such as regular, well characterised rigid-rod struc-
tures and outstanding thermal stabilities.1 A recent and import-
ant objective has been the incorporation of polyimides and
other polymer systems with dye-containing pendant groups,
research spurred on by the expectation that materials will be
obtained with excellent properties for use in optical devices.1–3
There is a parallel and burgeoning interest in macromolecules
incorporating transition metals; as well as desirable optical
properties, these materials offer unusual and potentially useful
magnetic or electrical properties.3–5
polymerisation reactions typical of aromatic diamines;1–3,14 and
(iii) results showing that oligomers and polymers are available
from L1 and its transition-metal complexes. Some of these
results have appeared in a preliminary communication.15
Results and Discussion
Synthetic studies
Synthesis of L1. Given the recent interest in transition-metal
complexes of terpyridines with 4Ј-pendants,5–12 it is surprising
that the ligand L1 has not been reported. However, we find that
L1 can be obtained by two methods (see Scheme 1): a con-
ventional one-pot condensation of poly(4-aminobenzaldehyde)
and 2 equivalents of 2-acetylpyridine or a two-step terpyridine
synthesis6,16 starting from 4-aminobenzaldehyde and two
equivalents of 2-acetylpyridine; here the 4-aminobenzalde-
hyde 17 was prepared immediately prior to the ligand prep-
aration and was handled in caustic-treated glassware (to prevent
its acid-catalysed self-condensation). In our hands, the two-step
synthesis was poorly reproducible and the reliable one-pot
condensation of poly(4-aminobenzaldehyde), which, con-
veniently, is commercially available, and 2-acetylpyridine is
preferred.
Bis(terpyridyl) transition-metal complexes6 are simply pre-
pared, more often than not are stable in more than one access-
ible oxidation state, and offer a wide spectrum of magnetic,7
photophysical8 and electrochemical properties.9,10 It is there-
fore no surprise that they have found much recent use as the
electroactive and chromophoric centres in supramolecular
assemblies.5,10–12 Other recent studies of photoinduced charge
separation in porphyrin–diimide assemblies and porphyrin–
diimide–quinone triads and tetrads show that the diimide
centres not only act as rigid spacers but also that they are
redox active and take part in the initial charge-separation pro-
cess by acting as electron acceptors to the singlet excited state
of the porphyrins.13 Taken together the above results suggest
that rigid-rod polymers formed from alternating bis(terpyridyl)
transition metal and diimide centres will have novel optical,
magnetic and/or electrical properties. Recent reports of the
novel photorefractive behaviour exhibited by polyimide poly-
mers with porphyrin centres interspersed throughout the poly-
mer chain 3 add further weight to this prediction and prompts
us to report: (i) the syntheses and properties of new redox-
active and chromophoric monomers of the general formula
Monomeric complexes of L1. Reactions of 2 equivalents of L1
with the appropriate metal chloride salt in methanol heated at
reflux for ≈15 min produced the complex cations [ML1 ]2ϩ
2
(M = Mn, Co, Ni, Cu or Zn), which were most conveniently
isolated as their hexafluorophosphate salts in 75–90% yield
after metathesis with saturated methanolic [NH4][PF6] and
recrystallisation from methanol. Reaction of RhCl3ؒ3H2O with
2 equivalents of L1 in boiling methanol followed by metathesis
with aqueous [NH4][PF6] afforded [RhL1 ][PF6]3 in 62% yield,
2
[ML1 ]nϩ where M is a transition metal and L1 is the new ligand
[FeL1 ]2ϩ was obtained in 80% yield as its tetrafluoroborate salt
2
2
4Ј-(4-anilino)-2,2Ј:6Ј,2Љ-terpyridine; (ii) model reactions of
directly from the reaction of [Fe(H2O)6][BF4]2 with 2 equiva-
[FeL1 ]2ϩ and [Ru(terpy)L1]2ϩ (terpy = 2,2Ј:6Ј,2Љ-terpyridine)
lents of L1 in methanol, and [RuL1 ][PF6]2 was obtained in 55%
2
2
with monofunctional organic reagents demonstrating that these
two complexes, and by inference all the complexes, undergo
yield from the reaction of L1 and [RuCl2(dmso)4] (dmso = di-
methyl sulfoxide) in aqueous ethanol heated at reflux for 3 h,
followed by metathesis with methanolic [NH4][PF6]. Reduction
of [Ru(terpy)Cl3] with triethylamine in the presence of L1 in hot
† Non-SI units employed: µB ≈ 9.27 × 10Ϫ24 J TϪ1, mmHg ≈ 133 Pa.
J. Chem. Soc., Dalton Trans., 1997, Pages 3011–3028
3011

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NH2
(iii )
NH2
NH2
m
o
(ii)
(i )
CHO
3′
3
6
4
5
N
O
O
O
O
N
N
N
N
N
N
L1
Scheme 1 (i) NaOH (aq), EtOH, 24 h; (ii) [NH4][O2CMe], EtOH, heat, 4 h, yield 14% overall for steps (i) and (ii); (iii) [NH4][O2CMe], acetamide,
heat, 2 h; NaOH (aq), heat 2 h; MeCO2H, 48% HBr (aq); NaHCO3, CHCl3, yield 12%
B
A
C
4
H
m
N
o
3
5
3′
O
6
N
N
M
N
B
A
[FeL3 2+: M = Fe(L3)2+
]
2
O
[Ru(terpy)L3 ]2+: M = Ru(terpy)2+
m
4
H
N
m
4
N
o
3
o
5
6
3
5
6
3′
3′
O
O
N
N
N
N
(ii )
N
N
M
M
(iii )
(i )
NH2
[FeL2 2+: M = Fe(L2)2+
]
2
[FeL4 2+: M = Fe(L4)2+
]
2
N
[Ru(terpy)L2 ]2+: M = Ru(terpy)2+
[Ru(terpy)L4 ]2+: M = Ru(terpy)2+
N
M
N
[FeL1 2+: M = Fe(L1)2+
]
2
[Ru(terpy)L1 ]2+: M = Ru(terpy)2+
Scheme 2 (i) Phthalic anhydride in dimethylacetamide followed by pyridine–acetic anhydride at 80 ЊC, or phthalic anhydride in N-
methylpyrrolidinone, 120 ЊC, 20 h; (ii) benzoyl chloride in acetonitrile–pyridine, heat; (iii) acetyl chloride in acetonitrile–pyridine, heat
aqueous ethanol, followed by addition of saturated aqueous
tetracarboxylic dianhydride)] and polyamides [from condens-
ation with bis(acid chlorides), e.g. terephthaloyl chloride].1,2,14
To investigate the feasibility of using L1 and its transition-metal
complexes in analogous oligomerisation or polymerisation
reactions, model reactions were carried out on L1 itself and on
[NH4][PF6], afforded [Ru(terpy)L1][PF6]2 in 55% yield.
Model oligomerisation/polymerisation reactions. There are
two general routes to oligomers or polymers derived from L1
and its transition-metal complexes: either (a) first preparing
a multinucleating terpyridyl ligand by coupling two or more
L1 together with a multifunctional organic reagent followed
by addition of metal ions to form the co-ordination oligomer
or polymer, or (b) linking preformed monomeric complexes
[FeL1 ]2ϩ and [Ru(terpy)L1]2ϩ. As expected, simple condens-
2
ations of L1 with phthalic anhydride or with benzoyl chloride
gave high yields (>90% raw yield; 65–70% isolated yield) of the
phthalimidophenyl and benzamidophenyl substituted ligands,
L2 and L3 respectively (see Scheme 2 for the ligand nomen-
of L1, e.g. [ML1 ]nϩ (M = transition-metal ion), with the same
clature adopted). Next the reactions of [FeL1 ]2ϩ and [Ru-
2
2
multifunctional reagent. Most successful syntheses of oligo-
mers linked by multinucleating terpyridyl ligands have been pre-
pared by preforming the ligand [route (a)], although Constable
and co-workers11a–d have recently reported some ether-linked
bis(terpyridyl)ruthenium oligomers prepared by route (b).
Two classes of polymer commonly formed from aromatic
diamines are polyimides [from condensation with bis(acid
dianhydrides), e.g. pyromellitic dianhydride (benzene-1,2:4,5-
(terpy)L1]2ϩ were investigated in order to establish whether or
not the reactivity of the anilino-function would be diminished
by co-ordination to the electrophilic metal centres. The reac-
tions attempted, conditions used and the nomenclature
adopted for the complexes of the new ligands are summarised
in Scheme 2. The raw yields of the imide complexes, [FeL2 ]2ϩ
2
and [Ru(terpy)L2]2ϩ, and the amide complexes, [FeL2]2ϩ and
1
[Ru(terpy)L]2ϩ (L = L3 or L4), ascertained by H NMR spec-
3012
J. Chem. Soc., Dalton Trans., 1997, Pages 3011–3028

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N
N
CO2H
H
N
O
N
N
N
H
O
HO2C
aa
N
N
N
N
N
N
N
N
N
N
N
O
N
N
O
N
N
H
H
O
O
O
O
p
p
H
H
N
O
O
m
N
m
o
m
o
o
3′
3′
3′
3
6
3
3
4
5
4
5
N
N
4
5
N
N
N
N
N
N
N
6
6
L7
L5
L6
troscopy (the solvent was stripped from the reaction mixture,
the resulting solid redissolved in deuteriated solvent and the 1H
NMR spectrum run), were high (90% and better). However,
isolated yields of these products dropped to around 50–60%
following purification by flash chromatography (silica support;
eluent acetonitrile–water–saturated aqueous KNO3 20:2:1)
and recrystallisation from a solution of an excess of [NH4][PF6]
in aqueous acetonitrile. If the chromatography step was omit-
ted and the crude solid obtained on removing the solvent from
the reaction mixture was recrystallised, much higher yields
(typically 70–85%) of equally pure product were obtained.
These results suggest that L1 and its complexes can be func-
tionalised in high yield but that losses occur during purification
of the crude product, and that chromatography needs to be
avoided if high yields are to be obtained. With this in mind,
studies of oligomer and polymer formation were begun.
yield. Diamidoaryl-bridged L6 was obtained in 70% isolated
yield from 2 equivalents of L1 with terephthaloyl chloride
in dimethylacetamide (dma)–pyridine (4:1) solution, and
diamidoalkyl-bridged L7 was obtained in 73% yield from 2
equivalents of L1 with adipoyl chloride in hot (120 ЊC) dma–
pyridine (4:1) solution. The new binucleating ligands, L5–L7,
were only sparingly soluble in high-boiling, polar aprotic solv-
ents, and in anhydrous trifluoroacetic acid. Nevertheless, sus-
pensions of them in boiling dimethylformamide (dmf) or boil-
ing ethane-1,2-diol dissolved when treated with 2 equivalents of
[Ru(terpy)(Me2CO)3]3ϩ {generated from [Ru(terpy)Cl3] and 3
equivalents of AgSbF6 in dry acetone} or with [Ru(terpy)Cl3]
respectively. Each of these reactions produced a mixture of
complexes which was separated by flash chromatography (silica
support; eluent MeCN–water–saturated aqueous KNO3
20:2:1), with the first band eluted yielding [Ru(terpy)2]2ϩ (8–
20%), the second impure [Ru(terpy)(L᎐L)]2ϩ (L᎐L = L5–L7) and
the third [(terpy)Ru(L–L)Ru(terpy)]4ϩ (L–L = L5–L7) (32–48%).
Secondly, route (b), linking preformed complexes of L1.
The dimer [(terpy)RuL5Ru(terpy)]4ϩ was also obtained from
[Ru(terpy)L1]2ϩ and pyromellitic dianhydride in dma at reflux,
followed by pyridine–acetic anhydride (1:2) to effect cyclo-
dehydration in 40% yield. The amido-bridged dimers,
[(terpy)Ru(L–L)Ru(terpy)]4ϩ (L–L = L6 or L7), were also
obtained from [Ru(terpy)L1]2ϩ and either terephthaloyl chloride
in dma–pyridine at reflux or adipoyl chloride in dmf–pyridine at
reflux in 44 and 30% yields respectively. Again, [Ru(terpy)2]2ϩ
was a product in these reactions.
Preliminary studies of oligomer and polymer formation. To
demonstrate both routes, (a) treating a preformed multinucleat-
ing terpyridyl ligand with a metal source and (b) linking pre-
formed transition-metal complexes of L1, in construction of
supramolecular architectures, we investigated the preparations
of three binuclear ruthenium() complexes, [(terpy)Ru(L᎐L)-
Ru(terpy)]4ϩ (L᎐L = L5–L7). First, route (a), preforming the
binucleating bis(terpyridyl) ligands. Reaction of two equiv-
alents of L1 with pyromellitic dianhydride in 1-methylpyrrol-
idin-2-one (nmp) at room temperature followed by addition of
acetic anhydride and pyridine and heating to 80 ЊC 14 to close
the intermediate amic acid (aa) produced L5 in 91% isolated
That [Ru(terpy)2]2ϩ was always a product in the above reac-
J. Chem. Soc., Dalton Trans., 1997, Pages 3011–3028
3013

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tions [for both routes (a) and (b)] indicates redistribution of the
terpyridyl ligands between metal centres occurs under the for-
cing reaction conditions,12 and this and the chromatography
necessary to separate these products combine to reduce the
overall yield of pure targeted dimer. In syntheses of higher
mixed-ligand oligomers, such processes will be exacerbated
leading to still lower yields. However, polymerisations using
either route(a)or (b)to formthehomopolymers[{M(L᎐L)}n]2nϩ [-
L᎐L = binucleating bis(terpyridyl) ligand] should avoid the
problems associated with ligand-scrambling reactions and are
described next.
N
O
O
H
N
N
N
N
N
H
N
N
L8
We investigated the preparations of the iron() homopoly-
mers, [{Fe(L᎐L)}n]2nϩ (L᎐L = L5᎐L7). Route (b): [FeL1 ][BF4]2
2
was coupled either with stoichiometric pyromellitic dianhydride
in dma at reflux, followed by pyridine–acetic anhydride (1:2) to
effect cyclodehydration 14 to give crude [(FeL5)n][BF4]2n, or with
terephthaloyl chloride or adipoyl chloride in dma–pyridine at
reflux to give crude [(FeL6)n][BF4]2n or [(FeL7)n][BF4]2n respect-
ively. Exhaustive extraction with methanol and with acetone to
remove lower-molecular-weight oligomers, followed by frac-
tional precipitation from dmf–CH2Cl2, afforded [(FeL5)n][BF4]2n
in 83% yield, [(FeL6)n][BF4]2n in 60% yield and [(FeL7)n][BF4]2n
in 52% yield. Route (a): a sample of [(FeL5)n][BF4]2n was also
obtained by treating the binucleating bis(terpyridyl) ligand L5
with equimolar [Fe(H2O)6][BF4]2 in boiling dma. This sample
was purified as above and displayed the same electronic and
NMR spectra (see below) as the material obtained by route (b).
The three co-ordination polymers were soluble in warm high-
boiling, polar, aprotic solvents such as dma, dmf, nmp and
dimethyl sulfoxide, and in anhydrous trifluoroacetic acid.
N
O
O
H
N
N
OEt
N
L9
obtained from reactions of L9 with CoCl2ؒ6H2O, [Fe(H2O)6]-
[BF4]2 and Zn(O2CMe)2 respectively, and reaction of [Ru(terpy)-
Cl3] with L9 in refluxing ethanol–water solution afforded
[Ru(terpy)L9]2ϩ. Final yields of the complexes after chromato-
graphy and recrystallisation were 45–65%.
Characterisation and properties of the new compounds
Attempted formation of poly(quinonylanilinoterpyridine)-
transition-metal oligomers and polymers. Polyquinonylamines
are an interesting group of redox-active polymers having poten-
tial as anticorrosion agents with the ability to displace water
from, for example, wet, rusty iron surfaces.18 These polymers
are formed in straightforward condensations (successive
Michael addition and oxidation reactions) of benzoquinone
with diamines. The success of the preliminary studies of oligo-
mer and polymer formation described above suggested that
Ligands. Only ligands L1–L3, L5–L7 and L9 were isolated. The
analytical and spectroscopic data for L1, isolated as stable, pale
yellow microcrystals (m.p. 256–257 ЊC), are fully in accord with
its formulation. It exhibited a broad amine N᎐H stretch at 3330
cmϪ1 in its IR spectrum and a molecular ion at m/z 324 in its
electron impact (EI) mass spectrum. The 1H NMR spectrum of
L1 shows peaks for each set of magnetically inequivalent pro-
tons (five pyridyl, two phenyl and the amine protons) and a 13C-
{1H} NMR spectrum reveals the expected 12 peaks. Likewise
the analytical and spectroscopic data are consistent for L2, L3,
poly(quinonylanilinoterpyridine)transition-metal
complexes
should also be available by two routes: (a) preforming the new
dinucleating terpyridyl ligand L8 by treating L1 with benzo-
quinone and then with appropriate metal sources, and (b) from
L5–L7 and L9. For example, the imide C᎐O band was found at
᎐
1740 cmϪ1 in the IR spectrum of L5, amide C᎐O peaks for L6
᎐
and L7 are observed at 1670 and 1655 cmϪ1 respectively, and L9
condensations of [ML1 ]2ϩ monomers with benzoquinone. The
shows a strong quinonyl C᎐O band at 1665 cmϪ1. The EI mass
᎐
2
attraction of co-ordination oligomers or polymers of L8 lies in
the fact that the quinonyl bridging group will be redox active
and potentially could act as an electron acceptor in systems
with photoactive bis(terpyridyl)-ruthenium or -osmium centres.
Unfortunately complexes of L8 were not available by either
spectra showed strong peaks for the expected molecular ions
1
and the H and 13C-{1H} NMR spectra revealed peaks for the
requisite number of magnetically inequivalent protons or car-
bon atoms, respectively, for the structures given for each ligand.
Absorption spectra of the ligands (Table 1) reveal a collection
of π → π* or n → π* bands (below ≈410 nm) which tail
into the visible region. The intense band at 497 nm in the elec-
tronic spectrum of L9 in methanol accounts for the red colour
of this ligand and is very likely centred on the anilinoquinone
group (for comparison, 2-anilino-1,4-benzoquinone in dmf
shows an intense band at 497 nm 19). The UV/VIS spectrum of
L1 is given in Fig. 1 along with examples of spectra of imide
(L2) and amide (L3) derivatives.
route. Route (b): the complexes [FeL1 ]2ϩ and [Ru(terpy)L1]2ϩ
2
were treated with benzoquinone under a variety of conditions,
for example heating at reflux in ethanol, always with the same
result, no reaction between the complexes and benzoquinone
was observed. We conclude that the nucleophilicity of the ani-
lino group(s) in the complex dications is reduced to the point
where Michael addition to benzoquinone does not occur.
Next, route (a), preforming L8. The literature procedure for the
formation of 2,5-dianilino-1,4-benzoquinone involves reaction
of stoichiometric quantities of benzoquinone and aniline in
ethanol heated at reflux.18,19 Using this procedure, equimolar
amounts of L1 and 1,4-benzoquinone afforded a dark red solid
in 34% yield following recrystallisation from ethanol which was
identified (see below) as the quinonylanilinoterpyridine ligand,
L9. Reactions of an excess of L1 with benzoquinone were also
tried and afforded L9 but none of the targeted binucleating
ligand, L8. As well, no reaction occurred between L1 and
benzoquinone in tetrahydrofuran or in acetic acid–water–
ethanol mixtures. Some complexes of L9 were prepared. The
Crystal structure of L1. The ligand L1 crystallised from
chloroform–methanol solution in the space group P21/c with
eight molecules in the unit cell. There are two independent mol-
ecules of L1, L1(A) and L1(B), in the crystal structure. Selected
bond length and angle data are listed in Table 2. Fig. 2 presents
a view of the crystal structure of L1 (down the c axis). The
crystal structure consists of oblique columns running parallel
to the a axis formed by offset π stacking between the terpyridyl
groups in anilino-tail-to-anilino-tail pairs of L1(A) alternat-
ing with anilino-tail-to-anilino-tail pairs of L1(B). The parallel
molecules within each of the tail-to-tail pairs of L1(A) and tail-
homoleptic complexes [ML9 ]2ϩ (M = Fe, Co or Zn) were
2
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J. Chem. Soc., Dalton Trans., 1997, Pages 3011–3028

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Table 1 Electronic spectral data for the ligands and complexes
Compound
λmax/nm (10Ϫ3 ε/l molϪ1 cmϪ1
)
L1 a
L2 a
L3 b
L5 b
L6 b
L7 b
L9 b
408 (11.3), 326 (16.8), 314 (15.8), 286 (24.4), 234 (22.2), 204 (35.5)
285 (38.5), 228 (36.9), 209 (38.2)
309 (sh, 18.9), 286 (20.6), 229 (19.5)
286 (12.5)
321 (34.6), 297 (sh, 34.4), 287 (35.3)
297 (36.7)
497 (3.8), 310 (sh, 21.8), 285 (30.7), 231 (24.9), 209 (31.4)
716 (sh, 0.20), 411 (53.9), 312 (66.3), 284 (84.6), 205 (141.6)
685 (0.10), 414 (46.8), 286 (44.2), 234 (37.6), 232 (63.6), 204 (90.1)
404 (61.1), 325 (67.7), 315 (63.7), 286 (95.8), 235 (91.9), 204 (140.5)
804 (0.13), 409 (54.3), 327 (32.5), 314 (34.9), 279 (53.5), 236 (45.0), 205 (92.2)
480 (43.4), 347 (24.0), 331 (32.0), 298 (52.8), 288 (52.0), 247 (42.8)
507 (44.1), 308 (97.7), 285 (57.6), 276 (53.1), 235 (46.1)
407 (46.9), 326 (44.5), 315 (40.4), 285 (59.6), 235 (61.0), 206 (84.2)
577 (30.2), 378 (26.9), 320 (51.3), 285 (47.7), 277 (39.7), 233 (sh, 35.8)
574 (22.7), 322 (46.7), 285 (41.9), 278 (34.1)
571 (34.1), 326 (77.2), 285 (62.7), 277 (50.5), 205 (109.5)
571 (27.4), 323 (62.0), 284 (51.7), 277 (42.0), 225 (sh, 45.0)
491 (33.0), 309 (94.0), 273 (51.2), 203 (84.1)
485 (25.8), 308 (76.6), 283 (41.8), 273 (44.7), 229 (sh, 40.2)
485 (32.3), 309 (95.8), 282 (56.2), 273 (60.2), 225 (sh, 58.0)
485 (25.9), 308 (78.3), 282 (49.5), 273 (53.5), 227 (sh, 42.6)
484 (46.9), 308 (151.5), 286 (sh, 102.5), 275 (98.1), 220 (105.1)
485 (47.4), 327 (sh, 95.6), 309 (130.4), 280 (sh, 69.7), 272 (77.3), 230 (sh, 75.0)
485 (41.3), 330 (sh, 79.0), 308 (126.8), 281 (79.9), 273 (86.3), 230 (sh, 69.0)
578, 326, 289
[CoL1 ][PF6]2
a
a
2
[CuL1 ][PF6]2
2
[MnL1 ][PF6]2
a
2
[NiL1 ][PF6]2
a
2
[RhL1 ][PF6]2
a
2
[RuL1 ][PF6]2
a
a
2
[ZnL1 ][PF6]2
2
[FeL1 ][BF4]2
a
2
[FeL2 ][BF4]2
a
2
[FeL3 ][BF4]2
a
a
2
[FeL4 ][BF4]2
2
[Ru(terpy)L1][PF6]2 a
[Ru(terpy)L2][PF6]2 a
[Ru(terpy)L3][PF6]2 a
[Ru(terpy)L4][PF6]2
a
[(terpy)RuL5Ru(terpy)][PF6]4 c
[(terpy)RuL6Ru(terpy)][PF6]4 c
[(terpy)RuL7Ru(terpy)][PF6]4
c
[(FeL5)n][BF4]2n
b
[(FeL6)n][BF4]2n
578, 325, 288
577, 317, 288
b
[(FeL7)n][BF4]2n
b
[CoL9 ][PF6]2
490 (17.5), 323 (53.9), 283 (70.5), 276 (sh, 65.9), 210 (91.6)
577 (36.1), 350 (sh, 55.0), 321 (57.2), 284 (66.6), 277 (58.8), 220 (sh, 51.3)
492 (13.7), 337 (sh, 59.4), 327 (61.3), 284 (77.1), 237 (65.4), 210 (88.2)
489 (25.5), 308 (69.5), 281 (46.1), 273 (50.0), 239 (sh, 33.7), 208 (59.8)
c
2
[FeL9 ][BF4]2
c
2
[ZnL9 ][PF6]2
c
2
[Ru(terpy)L9][PF6]2
c
a
In methanol. b In dmf. c In acetonitrile.
Fig. 2 Packing of the molecules in the crystal structure of compound
L1, viewed down the c axis
and C᎐N bond lengths within the aromatic rings are normal (in
the ranges 1.373 ± 0.025 and 1.353 ± 0.007 Å respectively) as
are the interannular C᎐C bond lengths (all in the range
1.48 ± 0.01 Å). The planar angles between the central and outer
pyridyl rings are 2.7 and 7.4Њ for L1(A) and 4.7 and 16.8Њ for
L1(B). The planar angle between the anilino and central pyridyl
groups is 27.4 and 27.5Њ for L1(A) and L1(B) respectively, con-
siderably more twisted than in 4Ј-phenyl-2,2Ј:6Ј,2Љ-terpyridine
(phterpy, the corresponding interannular planar angle is 10.9Њ)21
but less so than found in 4Ј-(2,5-dimethoxyphenyl)-2,2Ј:6Ј,2Љ-
terpyridine (dmpterpy, 50.4Њ).22
Fig. 1 The UV/VIS spectra of compounds L1–L3 in methanol
to-tail pairs of L1(B), which form the oblique plates that stack
to form each column, are related by crystallographic inver-
sion.The distance between the π-stacked terpyridyl groups is 3.5
Å. The molecules of L1 in adjacent columns are arranged in an
offset herringbone structure with respect to each other.
Complexes. The analytical and electrospray mass spectral
data for the complexes are consistent with their formulations
(full data are listed in the Experimental section). Electrospray
(ES) mass spectra of the monomeric complexes all showed
strong peaks for the parent molecular ion, [ML2]2ϩ (L = L1–L4,
L9 or terpy) and weaker peaks for the [ML2(PF6)]ϩ and [ML]2ϩ
ions. The ES-mass spectrum of each dimer showed peaks for
the [(terpy)Ru(L᎐L)Ru(terpy)]4ϩ parent ion, and for the parent
Both independent molecules of L1 display similar metrical
parameters. The molecular structure of L1(A) is shown in Fig.
3. In L1(A) and L1(B) the three pyridyl rings are approximately
coplanar and the pyridyl nitrogen atoms adopt the expected
transoid arrangement about the interannular bonds. The C᎐C
J. Chem. Soc., Dalton Trans., 1997, Pages 3011–3028
3015

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Table 2 Selected bond lengths (Å) and torsional angles (Њ) for com-
Table 3 Selected bond lengths (Å) and angles (Њ) for [CuL1 ][PF6]2 with
2
e.s.d.s in parentheses
pound L1 with estimated standard deviations (e.s.d.s) in parentheses
N(1A)᎐C(1A)
N(1A)᎐C(5A)
N(2A)᎐C(6A)
N(2A)᎐C(10A)
N(3A)᎐C(11A)
1.359(2)
1.346(2)
1.354(3)
1.358(3)
1.346(2)
N(3A)᎐C(15A)
N(4A)᎐C(19A)
C(5A)᎐C(6A)
C(8A)᎐C(16A)
C(10A)᎐C(11A)
1.359(2)
1.382(3)
1.479(2)
1.479(3)
1.481(2)
Cu᎐N(1A)
Cu᎐N(2A)
Cu᎐N(3A)
C(19A)᎐N(4A)
2.154(6) Cu᎐N(1B)
1.972(5) Cu᎐N(2B)
2.136(6) Cu᎐N(3B)
1.373(8) C(19B)᎐N(4B)
2.184(6)
1.986(5)
2.180(6)
1.393(9)
N(1A)᎐Cu᎐N(2A)
N(1A)᎐Cu᎐N(3A)
N(1A)᎐Cu᎐N(1B)
N(1A)᎐Cu᎐N(2B)
N(1A)᎐Cu᎐N(3B)
N(2A)᎐Cu᎐N(3A)
N(2A)᎐Cu᎐N(1B)
N(2A)᎐Cu᎐N(2B)
76.5(2) N(2A)᎐Cu᎐N(3B)
155.3(2) N(3A)᎐Cu᎐N(1B)
91.7(2) N(3A)᎐Cu᎐N(2B)
101.4(2) N(3A)᎐Cu᎐N(3B)
93.2(2) N(1B)᎐Cu᎐N(2B)
78.8(2) N(1B)᎐Cu᎐N(3B)
98.4(2) N(2B)᎐Cu᎐N(3B)
175.6(2)
107.1(2)
91.2(2)
103.1(2)
94.7(2)
77.7(2)
154.5(2)
76.8(2)
N(1A)᎐C(5A)᎐C(6A)᎐N(2A)
Ϫ172.6(1)
173.0(1)
27.2(2)
N(2A)᎐C(10A)᎐C(11A)᎐N(3A)
C(7A)᎐C(8A)᎐C(16A)᎐C(17A)
C(9A)᎐C(8A)᎐C(16A)᎐C(21A)
N(1B)᎐C(5B)᎐C(6B)᎐N(2B)
N(2B)᎐C(10B)᎐C(11B)᎐N(3B)
C(7B)᎐C(8B)᎐C(16B)᎐C(17B)
C(9B)᎐C(8B)᎐C(16B)᎐C(21B)
27.4(2)
Ϫ176.4(1)
Ϫ164.2(1)
Ϫ26.0(2)
Ϫ29.0(2)
C(18A)᎐C(19A)᎐N(4A) 121.4(8) C(18B)᎐C(19B)᎐N(4B) 120.3(9)
N(4A)᎐C(19A)᎐C(20A) 120.8(8) N(4B)᎐C(19B)᎐C(20B) 120.4(9)
not available and the polymers were insoluble in lower-boiling-
point solvents that are typically used for these measurements.1,23
However, the condensation of [FeL1 ][BF4]2 with pyromellitic
2
dianhydride with pyridine as the base to give [(FeL5)n][BF4]2n
could be quenched by addition of an excess of acetyl chloride
forming acetamide end-groups, thereby allowing 1H NMR spec-
troscopic determination of the average degree of polymeris-
ation (DP). Independently, [FeL1 ][BF4]2 was treated with acetyl
chloride and formation of the bis(4Ј-phenylacetamide) end-
2
Fig. 3 An ORTEP 20 plot of L1 (molecule A; 20% thermal ellipsoids for
non-hydrogen atoms)
capped complex was shown to be quantitative within detectable
1
limits by H NMR spectroscopy. A DP of 17.2 for [(FeL5)n]-
[BF4]2n which corresponds to an average molecular weight of
18 200 was obtained when the polymerisation was quenched
after 16 h. It should be noted that end-capping experiments only
give a lower estimate of the DP and average molecular weight.
Linear rigid-rod structures are favoured by the bonding and
by the steric and electrostatic interactions in the polycations,
[(FeL5)n]2nϩ. The length of the repeat unit is estimated to be
about 27.5 Å {using the sum of the distance between the two
N
N
NH
O
N
N
N
N
anilino nitrogen atoms in [CuL1 ]2ϩ (determined by X-ray crys-
2
L–L' = L10
tallography at 20.84 Å, see below) and 6.70 Å for the distance
between the nitrogen atoms in diphenylpyromellitimide (N,NЈ-
diphenylbenzene-1,2:4,5-dicarboximide)}. The cylindrical,
rigid-rod polycations, [(FeL5)n]2nϩ, with a DP of 17.2 thus have
an average length of about 473 Å and a radius of 5.8 Å (the
distance between the metal centre and the periphery of the
terpyridyl ligands).
ion–counter anion cluster ions, [(terpy)Ru(L᎐L)Ru(terpy) ϩ
PF6]3ϩ and [(terpy)Ru(L᎐L)Ru(terpy) ϩ 2PF6]2ϩ
.
For the polymers, [{Fe(L᎐L)}n][BF4]2n (L᎐L = L5–L7), ES
and matrix-assisted-laser-desorption-ionisation time-of-flight
(MALDI-TOF ) mass spectra were unrevealing as to the overall
polymer molecular weight. The highest mass peak in MALDI-
TOF mass spectra of the three polymers [{Fe(L᎐L)}n][BF4]2n
prepared by route (b) was for the [Fe(L᎐L)2]ϩ ion and no peaks
for [FeL1 ]2ϩ or [FeL1 ]ϩ ions were observed. Two conclusions
Crystal structure of [CuL1 ][PF6]2. Green crystals of
2
[CuL1 ][PF6]2 deposited from a solution of the complex in
2
acetone–methanol under an atmosphere of diethyl ether
vapour. The molecular structure of the cation and numbering
scheme adopted is depicted in Fig. 4 and selected bond angle
and length data are presented in Table 3.
2
2
can be made. (i) The complex [FeL1 ]2ϩ is completely consumed
2
in the condensation reactions and results in species with the
corresponding binucleating bis(terpyridyl) ligands, L5–L7. (ii)
Oligomeric ions are not observed, presumably these fragment
during the desorption-ionisation process because the co-
ordinate bonds to the first-row transition metal, iron(), ion are
relatively weak and labile. Some independent support for this
conclusion comes from the MALDI-TOF mass spectra of oli-
gomers of L10.22 For example, in MALDI-TOF mass spec-
trum of [(terpy)Ru(L᎐LЈ)Fe(LЈ᎐L)Ru(terpy)][PF6]6 (L᎐LЈ =
L10) by far and away the most intense peak is at m/z 993 for the
[Ru(terpy)L10]2ϩ fragment ion with peaks for the molecular
ion, M6ϩ, and molecular ion–counter anion cluster ions,
[M ϩ nPF6](6Ϫn)ϩ, being either very weak or not observed
(depending on conditions).
Estimates of average polymer molecular weights can some-
times be made from gel permeation chromatography (GPC)
measurements or from NMR detection of end-caps following
end-capping experiments.1,23 Unfortunately, meaningful GPC
measurements could not be obtained because GPC standards
appropriate for the rigid-rod polycations, [{Fe(L᎐L}n]2nϩ, are
The structure analysis revealed that [CuL1 ][PF6]2 crystallised
2
in the space group P212121 with four cations and eight anions,
all well separated from each other, in the unit cell. The cop-
per() ion displays the expected distorted-octahedral geometry
with intraligand bite angles in the range 76.5–78.8Њ. The planar
angle between central pyridyl rings of the two terpyridyl ligands
is 89.5Њ and the angle formed by the Cu atom and the nitrogen
atoms of the central pyridyl groups [N(2A)᎐Cu᎐N(2B)] is
175.6(2)Њ. All C᎐N and C᎐C distances are in the normal range.
The most notable feature of the structure is that the two terpyr-
idyl ligands, A and B, are inequivalent and show different bind-
ing to the copper ion. The two Cu᎐N (central pyridyl ring)
distances are similar at 1.972(5) (ligand A) and 1.986(5) (B), but
Cu᎐N (terminal pyridyl ring) distances for the two ligands are
significantly different, with those to ligand B [average 2.182(6)
Å] elongated compared to those for A [average 2.154(6) Å]. The
same orthorhombic distortion from octahedral symmetry is
24
observed in [Cu(terpy)2][NO3]2 and [Cu(dmpterpy)2][BF4],22
3016
J. Chem. Soc., Dalton Trans., 1997, Pages 3011–3028

View Article Online
Fig. 4 An ORTEP plot of the cation [CuL1 ]2ϩ (20% thermal ellipsoids for non-hydrogen atoms)
2
and has been attributed to the compromise between tetragonal
compression along the axis roughly defined by N(2A), Cu and
N(2B) as a result of the rigid terpyridine ligands and a tetra-
gonal elongation along the axis roughly defined by N(1B), Cu
and N(3B) as a consequence of the Jahn–Teller effect.24 The
inequivalence of the two terpyridyl ligands is also revealed by
the planar angles (and interannular distances) between the cen-
tral pyridyl and anilino rings within each ligand [17.8Њ (1.468 Å)
for ligand A and 38.2Њ (1.503 Å) for B]. The corresponding
interannular twist and distance in free L1 (see above) lie midway
between those observed for ligands A and B in the [CuL1 ]2ϩ
2
cation. This suggests that, compared to free L1, the π overlap
between the central pyridyl and anilino rings is increased in
ligand A and decreased in B.
Magnetism and NMR spectroscopy. The complexes [ML1 ]2ϩ
2
(M = Mn, Co, Ni or Cu) are paramagnetic and Table 4 lists
both the solution magnetic moment data ascertained using the
Evans method 25 and the ambient-temperature solid-state data.
The magnetic moment data for the complexes MnII, NiII and
CuII agree with expected values for high-spin octahedral com-
Fig. 5 Temperature-dependent magnetic moment data for [CoL1 ]-
[PF6]2ؒ2H2O in acetone solution
2
plexes. The magnetic moment of [CoL1 ][PF6]2 in acetone solu-
2
tion varied significantly with temperature as shown in Fig. 5.
Octahedral cobalt() complexes show magnetic moments in the
range 4.8–5.2 µB for high-spin complexes and 2.0–2.5 µB for low-
spin complexes. The intermediate and decreasing values for the
Table 4 Magnetic moments (µB) at 295 K
[CoL1 ]2ϩ ion over the temperature range 310 (µeff = 3.67) to
Complex
Acetone solution
Solid state
2
[CoL1 ][PF6]2
3.34
2.36
5.97
3.34
3.23
2.07
6.35
3.41
210 K (2.61 µB) are consistent with an incomplete, broad
continuous spin transition. Other bis(terpyridyl)cobalt() com-
plexes show similar magnetic behaviour.7
[CuL12][PF6]2
2
[MnL1 ][PF6]2
2
[NiL1 ][PF6]2
2
Proton NMR data for the diamagnetic complexes are sum-
marised in Table 5. The monomeric complexes, [ML2]2ϩ (L = L1,
M = Fe, Ru or Zn; L = L2–L4, M = Fe; L = L9, M = Fe or Zn),
NMR spectra reported for other ruthenium() complexes of 4Ј-
[RhL1 ]3ϩ and [Ru(terpy)L]2ϩ (L = L1–L4 or L9), and the dimers,
substituted terpyridyl ligands.11,26 As examples of assigned H
1
2
[(terpy)Ru(L᎐L)Ru(terpy)]4ϩ (L᎐L = L5–L7), gave 1H NMR
spectra that agree with their indicated structures. Assignments
of the 1H NMR spectra were easily made with the aid of double
quantum filtered correlation (DQF-COSY) 1H᎐1H NMR spec-
NMR spectra, those for the dimers are shown in Fig. 6. Notable
features from the 1H NMR spectra are: (i) as expected, protons
H6 closest to the metal centre are most affected as the metal
centre is changed in the [ML1 ]nϩ complexes {e.g. δ(H6) is 7.55
2
1
tra of selected complexes and using comparisons with the H
for [FeL1 ]2ϩ whereas δ(H6) is 8.30 for [RhL1 ]3ϩ}; (ii) in the
2
2
J. Chem. Soc., Dalton Trans., 1997, Pages 3011–3028
3017

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1
Fig. 7 The 300 MHz H NMR spectra recorded in (CD3)2SO of the
polymers, [{Fe(terpy)(L᎐L)}n][BF4]2n: L᎐L = L5 (a), L6 (b) and L7 (c)
Fig. 6 The 300 MHz 1H NMR spectra of the dimers, [(terpy)Ru(L᎐L)-
Ru(terpy)]4ϩ, recorded in (CD3)2SO: L᎐L = L5 (a), L6 (b) and L7 (c)
[ML1 ]nϩ complexes, the largest co-ordination changes in chem-
2
ical shift (∆δ = δcomplex Ϫ δfree ligand) were for the NH2 protons
(∆δ varied from 1.51 to 1.93 ppm) followed by the H6 protons
(∆δ varied from Ϫ0.33 to Ϫ1.18 ppm) and H3Ј protons (∆δ
varied from 0.52 to 0.78 ppm) with the magnitudes |∆δ| for all
other protons being less than 0.4 ppm; (iii) in the heteroleptic
complexes, independent peaks are observed for both terpyridyl
domains; and (iv) in complexes of L1, the two peaks for the NH2
protons likely result from facile exchange of these protons with
the deuteriated solvent to give the isotopomers, NH2 (observed,
one peak), NHD (observed, one peak) and ND2 (not observed).
Both peaks were lost on shaking with D2O. In some 13C-{1H}
NMR spectra less than the requisite number of peaks for mag-
netically non-equivalent carbon atoms were observed. This is
attributed to chemical shift coincidence of some of the peaks.
Finally, the 1H NMR spectra of the polymeric cations [{Fe(L᎐
L)}n]2nϩ (L᎐L = L5–L7) reveal the correct number of broad
peaks at positions roughly corresponding to the chemical shift
of the analogous protons in the 1H NMR spectra of the
[FeL2]2ϩ (L = L2–L4) model compounds (compare Figs. 6 and
7). Broadening of the peaks is expected for the polymeric cat-
ions due to the decreased mobility and increased correlation
times in solution.23
Fig. 8 The UV/VIS spectra of [ZnL1 ][PF6]2
2
intensity, e.g. Fig. 8. These bands and weak d–d bands contrib-
ute to the observed colours of the complexes. The weak bands
shown in Fig. 9 in the visible or near-infrared regions of spectra
for the complexes [ML1 ]2ϩ (M = Co, Ni or Cu) are attributed
2
to d–d transitions by comparison with literature assignments
for analogous terpy or phterpy complexes.6–9,21 In absorption
spectra of L1 and its complexes the lowest-energy ligand-
centred band at ≈405 nm is solvatochromic, shifting in energy
Colour and absorption spectra. Owing to their potential as
pigments for incorporation into macromolecules the colours of
the complexes are of some interest. They cover a large portion
with solvent. For example, spectra of [ZnL1 ]2ϩ in methanol and
2
acetonitrile are reproduced in Fig. 8. This behaviour was not
investigated further because of the poor solubility of L1 and its
complexes in less polar solvents. The intense ligand-centred
band at ca. 495 nm in the UV/VIS spectra of L9 and its com-
plexes also shifts in energy (±10 nm) with solvent.
of the visible spectrum. For example, the [ML1 ]nϩ complexes
2
range from intense red (RuII), dark orange (RhIII), yellow-brown
(NiII), yellow (MnII), through pale yellow (ZnII) and green
(CuII) to maroon (CoII) and deep purple (FeII).
Data from UV/VIS spectra of the complexes are presented in
The visible regions of the absorption spectra of the iron,
ruthenium, cobalt and rhodium complexes are dominated by
intense charge-transfer bands and there are accompanying
Table 1. The complexes [ML1 ]2ϩ (M = Mn, Ni, Cu or Zn) show
2
the same bands as free L1 (see above) but with about twice the
3018
J. Chem. Soc., Dalton Trans., 1997, Pages 3011–3028

Table 5 The 300 MHz 1H NMR data (δ) for the diamagnetic complexes
terpy derivative
terpy
H3Ј
Compound
L1 a
H3Ј
H3
H4
H5
H6
Ho
Hm
NH
3.89
5.48, 5.47
5.82, 5.81
5.41, 5.39
5.53, 5.52
Other
H4Ј
H3
H4
H5
H6
8.69
9.47
9.42
9.28
9.21
9.79
9.75
9.67
9.63
9.33
9.28
9.45
9.36
9.35
9.41
9.62
9.16
9.16
8.66
8.97
9.17
9.00
9.06
9.12
9.14
9.08
9.00
9.04
8.99
9.03
9.16
8.98
9.01
9.16
9.55
9.55
7.87
8.03
8.42
8.06
8.27
8.11
8.09
8.06
8.04
8.04
8.06
8.04
8.07
8.03
8.04
8.12
8.11
8.11
7.34
7.24
7.63
7.32
7.52
7.27
7.24
7.22
7.22
7.47
7.32
7.30
7.32
7.28
7.29
7.34
7.33
7.33
8.73
7.55
8.30
7.79
8.17
7.36
7.34
7.31
7.55
8.16
7.66
7.69
7.47
7.66
7.68
7.52
7.49
7.49
7.78
8.26
8.21
8.13
8.17
8.74
8.68
8.57
8.51
8.35
8.13
8.40
8.56
8.25
8.39
8.68
8.60
8.60
6.80
7.03
6.99
6.98
6.98
7.99
8.31
8.06
7.83
7.73
6.98
7.88
8.26
7.96
7.77
8.01
8.28
8.28
b
[FeL1 ][BF4]2
2
[RhL1 ][PF6]2
b
b
2
[RuL1 ][PF6]2
2
[ZnL1 ][PF6]2
b
2
[FeL2 ][BF4]2
8.11, 8.04
8.13, 7.72, 7.66
2.78
6.16, 6.01, 4.13, 1.41
6.08, 5.95, 4.06, 1.35
c
2
[FeL3 ][BF4]2
10.78
10.40
c
2
[FeL4 ][BF4]2
c
2
[FeL9 ][BF4]2
b
2
[ZnL9 ][PF6]2
b
2
[Ru(terpy)L1][PF6]2 b
[Ru(terpy)L2][PF6]2 c
[Ru(terpy)L3][PF6]2 b
[Ru(terpy)L4][PF6]2 b
[Ru(terpy)L9][PF6]2
5.41, 5.40
9.06
9.06
9.16
9.03
9.05
9.16
9.16
9.15
8.54
8.55
8.57
8.53
8.55
8.60
8.60
8.59
8.80
8.78
8.91
8.77
8.78
8.91
8.90
8.89
8.08
8.04
8.11
8.03
8.04
8.12
8.11
8.07
7.34
7.30
7.32
7.28
7.30
7.34
7.33
7.31
7.81
7.78
7.69
7.76
7.77
7.61
7.61
7.59
b
8.01, 7.95
8.11, 7.66, 7.64
2.78
6.11, 6.00, 4.11, 1.40
8.60
10.59
9.50
[(terpy)RuL5Ru(terpy)][PF6]4 c
[(terpy)RuL6Ru(terpy)][PF6]4 c
[(terpy)RuL7Ru(terpy)][PF6]4
c
10.85
10.38
8.28
2.59, 1.88
a
Recorded in CDCl3. b Recorded in (CD3)2CO. c Recorded in (CD3)2SO.

View Article Online
Fig. 11 Cyclic voltammogram of [ZnL1 ][PF6]2 in acetonitrile–0.1 mol
2
l
Ϫ1 [NBun4][PF6] at a platinum-disc working electrode (scan rate 100 mV
)
sϪ1
Electrochemical behaviour. The voltammetric behaviour of
the ligands (Table 6) and the complexes (Tables 7 and 8) was
probed by cyclic and differential pulse voltammetries.
Fig. 9 The VIS/NIR spectra in acetone for (a) [CoL1 ][PF6]2, (b)
2
[NiL1 ][PF6]2 and (c) [CuL1 ][PF6]2
2
2
Cyclic voltammograms of ligand L1 in acetonitrile solution
show an irreversible oxidation process at ϩ0.88 V and no other
distinct processes over the potential range ϩ2.0 to Ϫ2.3 V. Bulk
electrolysis revealed the oxidation to be a two-electron process.
Given the absence of such an oxidation process in phterpy,21 it
seems likely that the process is centred on the anilino-group.
Under analogous aprotic conditions, aniline also displays an
irreversible two-electron oxidation (at ≈ϩ0.66 V).27 We assume
that the anticipated one-electron reduction of the terpyridyl
centre takes place at potentials negative of Ϫ2.3 V.
Each monomeric complex shows the voltammetric responses
expected for the respective M(terpy)2nϩ core, typically MIII᎐MII
and/or MII᎐MI couples and two terpyridyl-centred reduc-
tion processes {the [M(terpy)2]nϩ–[M(terpy)(terpyϪ)](nϪ1)ϩ
and [M(terpy)(terpyϪ)](nϪ1)ϩ–[M(terpyϪ)2](nϪ2)ϩ couples}. The
voltammetric responses for the [M(terpy)2]nϩ cores are rela-
tively well known 9 and, rather than detailed description, assign-
ments are summarised in Table 6. In addition to the [M(terpy)2]nϩ
core processes, an irreversible anilino-centred oxidation was
observed between ϩ0.62 to ϩ0.92 V for the complexes [ML1 ]nϩ
,
2
e.g. Fig. 11. Complexes of the phthalimido-ligand L2 and amido-
ligands L3, L4 showed irreversible oxidations at ≈ϩ1.5 V. A
phthalimido-centred reduction couple at ≈Ϫ1.8 V was also
observed for complexes of L2. Since the oxidation of the anilino-
group precedes the MIII᎐MII couple in the iron and ruthenium
complexes, the influence of the anilino-group on these couples
cannot be judged. However, comparison of the CoIII᎐CoII and
Fig. 10 The UV/VIS spectra of listed complexes in methanol solution
changes in the relative intensities of the ligand-centred bands,
e.g. Fig. 10. The intense bands in the visible region for the iron
and ruthenium complexes are the result of spin-allowed
CoII᎐CoI couples for [CoL1 ]2ϩ (E = Ϫ0.24 and Ϫ1.25 V) with
₁
2
₂
those for [Co(phterpy)2]2ϩ (E = Ϫ0.15 and Ϫ1.20 V)28 and [Co-
₁
₂
28
₁
dπ(M) → π*(terpy),
metal-to-ligand
charge-transfer
(terpy)2]2ϩ (E = Ϫ0.13 and Ϫ1.18 V) reveals that the donor
₂
(1MLCT) transitions.8,10 The MLCT bands of the iron and
ruthenium complexes are all red-shifted and considerably more
intense than the MLCT bands observed for [Fe(terpy)2]2ϩ and
[Ru(terpy)2]2ϩ. This red-shift is small (р15 nm) and repro-
ducibly larger for complexes of L1 (by ≈6 nm) than for com-
plexes of the imido or amido functionalised ligands, L2–L7.
Red-shifted MLCT band maxima are characteristic of bis-
(terpyridyl)ruthenium() complexes with the ligands substi-
tuted at the 4Ј-positions by either donor or acceptor groups.
The effect arises because electron-accepting groups stabilise the
π*(terpy) lowest unoccupied molecular orbital (LUMO) more
than the dπ metal highest occupied molecular orbital (HOMO)
whereas electron-donating groups cause a larger destabilisation
of the dπ metal HOMO than the π*(terpy) LUMO.8 The MLCT
band maxima are thus consistent with the anilino group in L1
being a better donor group than the benzimido or the benz-
amido groups in L2–L7.
anilino moiety stabilises the higher oxidation state in each
couple. Cyclic voltammograms of L9 and its complexes show an
anodic peak at ≈ϩ1.1 V ascribed to irreversible oxidation of the
anilinoquinone group(s) (for comparison, 2-anilino-1,4-benzo-
quinine shows an irreversible oxidation process at ≈ϩ1.4 V17,18).
Not all of the [M(terpy)2]nϩ core processes anticipated for the
complexes of L9 could be assigned (Table 7) because cyclic
voltammograms to potentials negative of ≈Ϫ1.0 V were domin-
ated by complicated adsorption and stripping peaks.
Cyclic voltammograms of the dimers [(terpy)Ru(L᎐L)-
Ru(terpy)]4ϩ (L᎐L = L5–L7) have been published in a preliminary
communication 15 and data are given in Table 8. Each of the
dimers shows a combination of the redox processes expected
for two electrochemically isolated [Ru(terpy)(terpyϪ)]2ϩ centres
(one RuIII᎐RuII couple at ≈ϩ0.9 V and two terpy–terpyϪ
couples at approximately Ϫ1.7 and Ϫ1.9 V, each with a two-
electron peak current) and for the intervening organic linkage13
3020
J. Chem. Soc., Dalton Trans., 1997, Pages 3011–3028

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Table 6 Electrochemical data for the ligands; potentials (V) are versus
the ferrocenium–ferrocene couple
Reduction
Oxidation
Ea
Ligand
Solvent a
E1
E2
E3
L1
L2
L3
L6
L9
MeCN
MeCN
dmf
dmf
MeCN
0.88b
1.93b
0.61b
0.65b
1.0b
Ϫ1.79c
Ϫ2.25
Ϫ2.36
Ϫ2.58
Ϫ2.73
Ϫ0.84b,d
Ϫ0.88b,d
a
Solvent containing 0.1 mol lϪ1 [NBun4][PF6]. b Irreversible process.
c Imide-centred reduction. d Coupled with Ea.
have been developed. The failure of the complexes of L1 to
react with benzoquinone suggests a potential limitation, lower
than usual nucleophilicity for the anilino group in these sys-
tems. Nevertheless, we believe that straightforward extensions
of the successful syntheses described herein should provide a
wide variety of interesting multicomponent bis(terpyridyl)
transition-metal systems for future studies.
Experimental
All reactions were carried out under an atmosphere of dry di-
nitrogen unless otherwise stated, using standard Schlenk and
cannula techniques. Solvents were routinely distilled from an
appropriate drying agent immediately prior to use. Acetonitrile
was distilled from calcium hydride; dmf was dried over calcium
hydride and then distilled under reduced pressure; methanol
and ethanol were distilled from magnesium turnings, nmp was
distilled from phosphorus pentaoxide; pyridine was distilled
from barium oxide and stored over barium oxide under dinitro-
gen. Anhydrous dma stored under an inert atmosphere was
purchased from Aldrich Chemical company and used as
received. Acetone was distilled from potassium permanganate
and then from boric oxide. The solvents used for electro-
chemical measurements, acetonitrile and dimethylformamide,
were highest-quality anhydrous grade sealed under argon
(Aldrich) and were used as obtained.
Fig. 12 Cyclic voltammograms in acetonitrile–0.1 mol lϪ1 [NBun4]-
[PF6] at a platinum-disc working electrode (scan rate 100 mV sϪ1) or the
polymers, [{Fe(L᎐L)(terpy)}n][BF4]2n: L᎐L = L5 (a), L6 (b) and L7 (c)
{[(terpy)RuL5Ru(terpy)]4ϩ: an irreversible oxidation at ϩ0.65 V
and two reversible one-electron reductions centred at the
pyromellitimido linkage at Ϫ1.13 and Ϫ1.79 V; [(terpy)RuL6-
Ru(terpy)]4ϩ: irreversible oxidation of the terephthalamido
linking group at ≈ϩ0.9 V (overlaps with the RuIII᎐RuII couple);
[(terpy)RuL7Ru(terpy)]4ϩ: irreversible amido-centred oxidation
at ϩ0.65 V}.
In cyclic voltammograms of the polymers, Fig. 12, the
FeIII᎐FeII couples and irreversible imido- or amido-oxidation
processes merge to give poorly reversible oxidation features at
≈ϩ0.63 V. Distinct terpyridine-centred reduction couples are
no longer observed. Rather, the cyclic voltammograms of the
three polymers reveal a poorly reversible reduction process at
≈Ϫ2.3 V (near the cathodic solvent discharge). The complex
[(FeL7)n]2nϩ also exhibits a broad irreversible reduction at Ϫ1.55
V. The reason(s) for the poor reversibility of the electrochemical
responses of the polymers is not well understood. Similar
poorly reversible electrochemical behaviour is exhibited by
dendrite-coated bis(terpyridine)-iron() and -ruthenium()
complexes.29 The irreversibility of the electrochemical processes
in these systems was attributed to inhibition of electron transfer
between the electrode and the metal centres by the insulating
dendritic coating. We speculate that the morphologies of the
[{Fe(L᎐L)}n]2nϩ polycations may prevent close approach of
most of the redox centres in each polycation to the electrode
thereby providing a barrier to electron transfer between the
electrode and the redox centres.
Flash chromatography was carried out using Merck silica gel
7730 60GF254. Columns were packed with dry gel; solvent was
applied to the column before a concentrated solution of the
sample in the appropriate solvent. A water aspirator was
attached to the receiving flask during packing and elution.
Quoted melting points are uncorrected. Microanalyses (for C,
H and N) were performed by the University of New South
Wales microanalytical service. Prior to analysis, samples were
dried at 40 ЊC for 48 h under vacuum (0.2 mmHg) over phos-
phorus pentaoxide. Electron ionisation and electrospray mass
spectra were recorded using a VG Quattro mass spectrometer
and matrix-assisted-laser-desorption-ionisation time-of-flight
mass spectra were recorded on a Finnigan Lasermat instrument
using a matrix of either α-cyano-4-hydroxycinnamic acid or
sinapinic acid [HOC H (OMe) CH᎐CHCO H]. Proton and 13
C
᎐
6
2
2
2
NMR spectra were obtained in the designated solvents on a
Bruker AC-F 300 (300 MHz) instrument, infrared spectra as
Nujol mulls on a Perkin-Elmer 580B spectrometer (only the
most prominent peaks are reported) and electronic spectra
using a CARY 5 spectrophotometer in the dual-beam mode.
Solution measurements of magnetic moments were determined
in acetone solution using the Evans method 25 on a Bruker
AC-F 300 (300 MHz) NMR spectrometer. Electrochemical
measurements were recorded using a Bioanalytical Systems
(BAS) 100B Electrochemical Analyser interfaced to a 486 IBM-
compatible personal computer. Data were transferred to a
Macintosh Power PC 7600 computer for processing using the
IGORPRO 2.0TM software.30 Cyclic and differential pulse vol-
tammetries were conducted in a standard three-electrode cell
Conclusion
These results reveal transition-metal complexes of L1 to be
readily obtainable and to display a wide variety of chromo-
phoric, magnetic and electrochemical properties. The model
reactions demonstrate that the pendant aniline groups in com-
plexes of L1 can be readily functionalised using standard
organic synthetic methods, and techniques for preparations of
metallodimers and metallopolymers using L1 and its complexes
J. Chem. Soc., Dalton Trans., 1997, Pages 3011–3028
3021

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Table 7 Electrochemical data for the monomeric complexes in MeCN containing 0.1 mol lϪ1 [NBun4][PF6]; potentials (V) are versus the
ferrocenium–ferrocene couple
Complex
MII᎐MIII
Ϫ0.24
MII᎐MI
Ϫ1.25
Ea
E1
E2
E3
[CoL1 ]2ϩ
0.77
0.82
0.82
0.72
0.85
0.74
0.92
0.62
1.54
1.45
1.54
0.63
1.87
1.36
1.45
1.27
1.23
1.26
1.12
Ϫ2.08
[CuL12]2ϩ
Ϫ0.72
2
[MnL1 ]2ϩ
Ϫ1.54
Ϫ1.75
Ϫ1.81
Ϫ1.93
2
[NiL1 ]2ϩ
2
[RhL1 ]3ϩ
[RuL1 2]2ϩ
[ZnL12]2ϩ
[FeL1 2]2ϩ
[FeL22]2ϩ
[FeL32]2ϩ
Ϫ1.06a
0.96
Ϫ1.70
Ϫ1.70
Ϫ1.70
Ϫ1.60
Ϫ1.66
Ϫ1.64
Ϫ1.68
Ϫ1.63
Ϫ1.68
Ϫ1.65
Ϫ1.94
Ϫ1.84
Ϫ1.78
Ϫ1.71
Ϫ1.78
Ϫ1.73
Ϫ1.93
Ϫ1.91
Ϫ1.95
Ϫ1.90
0.69
0.69
0.68
0.68
0.91
0.88
0.86
0.86
Ϫ0.15
0.68
Ϫ1.81b
Ϫ1.44c
[FeL42]2ϩ
2
[Ru(terpy)L1]2ϩ
[Ru(terpy)L2]2ϩ
[Ru(terpy)L3]2ϩ
[Ru(terpy)L4]2ϩ
Ϫ2.43d
Ϫ2.44d
Ϫ2.44d
[CoL9 ]2ϩ
2
[FeL9 ]2ϩ
2
[ZnL9 ]2ϩ
2
[Ru(terpy)L9]2ϩ
0.89
a
Ea = Irreversible oxidation process; E1, E2 = first and second terpyridyl-centred reduction couples. RhIII᎐RhI couple. b Imide-centred reduction.
c Coupled with Ea. d Data from differential pulse voltammetry.
Table 8 Electrochemical data for the ruthenium() dimers and iron() polymers in dmf containing 0.1 mol lϪ1 [NBun4][PF6]; potentials (V)
are versus the ferrocenium–ferrocene couple
Complex
MII᎐MIII
Ea
E1
E2
E3
[(terpy)RuL5Ru(terpy)]4ϩ
[(terpy)RuL6Ru(terpy)]4ϩ
[(terpy)RuL7Ru(terpy)]4ϩ
[Ru(terpy)L1]2ϩ
0.78
0.9b
0.79
0.82
0.63
0.63
0.61
0.65
Ϫ1.68
Ϫ1.68
Ϫ1.67
Ϫ1.70
Ϫ1.92
Ϫ1.92
Ϫ1.91
Ϫ1.92
Ϫ1.13,a Ϫ1.79a
Ϫ0.85c
0.65
0.58
Ϫ0.81c
[(FeL5)n]2nϩ
[(FeL6)n]2nϩ
[(FeL7)n]2nϩ
a
Ea = Irreversible oxidation; E1 and E2 = first and second terpy-core reductions. Imide-centred reduction. b Overlap of irreversible amide oxidation
and RuII᎐RuIII couple. c Coupled with Ea.
consisting of a platinum-disc working electrode (0.8 mm diam-
eter, BAS), platinum-wire (0.05 mm diameter) auxiliary elec-
trode and a Ag–AgCl reference electrode (BAS). All potentials
are quoted relative to the ferrocenium–ferrocene couple which
was measured in situ as an internal reference.
mmol) and ammonium acetate (5.0 g) were heated at reflux in
ethanol (100 cm3) for 4 h. After cooling, water (50 cm3) was
added and the reaction mixture was condensed to 60 cm3 in
vacuo. After standing for 1 h the resulting solid was collected and
then recrystallised from ethanol, filtered off and washed with
diethyl ether to give a light yellow crystalline solid (0.17 g, 60%).
Method 2. Poly(4-aminobenzaldehyde) (9.7 g, 0.08 mol), 2-
acetylpyridine (22 cm3, 0.17 mol), ammonium acetate (75 g,
0.98 mol) and acetamide (100 g, 1.7 mol) were heated in air at
reflux for 3 h at 180 ЊC. The solution was allowed to cool and
then NaOH (50 g) in water (200 cm3) was added and the mix-
ture heated at reflux for 2 h. After cooling the solution was
decanted and the oily solid washed with water (3 × 200 cm3).
The sludge was dissolved in the minimum volume of hot con-
centrated hydrobromic acid, and then the solution allowed to
stand at room temperature for 16 h. The dark brown precipitate
was filtered off, placed in a beaker with water (300 cm3) and
NaHCO3 added until the solution was basic. The solid was
extracted into chloroform, concentrated and purified by flash
chromatography (silica, chloroform as the eluent). The brown
band (fraction 3) was collected and concentrated to a brown oil
that was recrystallised from a chloroform–methanol mixture to
give transparent brown crystals (3.1 g, 12%). The other frac-
tions separated by chromatography were not identified. M.p.
256–257 ЊC (Found: C, 77.72; H, 5.15; N, 17.00. Calc. for
C21H16N4: C, 77.78; H, 4.94; N, 17.28%). EI mass spectrum: m/z
324 (Mϩ) and 246 (Mϩ Ϫ py). 1H NMR (CDCl3): δ 8.73 (br d, 2
H, J = 4.6, H6), 8.69 (s, 2 H, H3Ј), 8.66 (d, 2 H, J = 8.0, H3), 7.87
(td, 2 H, J = 7.7, 1.8, H4), 7.78 (d, 2 H, J = 8.5, Ho), 7.34 (ddd, 2
H, J = 7.7, 4.7, 1.2, H5), 6.80 (d, 2 H, J = 8.5 Hz, Hm) and 3.90
(br s, NH2). 13C NMR (CDCl3): δ 157.18, 156.37, 150.62, 149.74
Preparations
3-(4-Anilino)-1,5-bis(2-pyridyl)pentane-1,5-dione.
Freshly
prepared p-aminobenzaldehyde (4.46 g, 36.8 mmol) was dis-
solved in ethanol (250 cm3) and NaOH (3.0 g) in water (30 cm3)
added. 2-Acetylpyridine (8.5 cm3, 80 mmol) was added dropwise
and the solution stirred at room temperature for 80 h. During
this period a precipitate formed and this was filtered off and
washed with water then diethyl ether. The crude product was
recrystallised from ethanol to give a yellow-brown microcrystal-
line solid (3.21 g, 20%), m.p. 153–155 ЊC (Found: C, 72.93; H,
5.78; N, 12.00. Calc. for C21H19N3O2: C, 73.04; H, 5.51; N,
1
12.17%). EI mass spectrum: m/z 345 (Mϩ). H NMR (CDCl3):
δ 8.63 (d, 2 H, J = 4.6, H6), 7.93 (d, 2 H, J = 8.0, H3), 7.76 (td, 2
H, J = 7.7, 1.5, H4), 7.41 (ddd, 2 H, J = 7.4, 4.6, 1.5, H5), 7.13 (d,
2 H, J = 8.5, Ho), 6.56 (d, 2 H, J = 8.5 Hz, Hm), 4.05 (m, 1 H,
CH), 3.63 (br m, 2 H, CH2) and 3.49 (br s, 2 H, NH2). 13C NMR
(CDCl3): δ 200.9 (C2Ј), 154.2, 148.8 (C6), 145.0, 136.7 (C4), 135.4,
128.5, 126.9, 121.8 (C5), 115.2 (C3), 44.4 (C4Ј) and 35.4 (C3Ј). IR
(Nujol mull): 3395w, 1797s, 1786s, 1584m, 1515m, 1391m,
1278m, 995s, 780m and 771m cmϪ1. UV/VIS (MeOH): λmax/nm
(10Ϫ3 ε/l molϪ1 cmϪ1) 202 (29.0), 233 (21.5) and 269 (8.9).
4Ј-(4-Anilino)-2,2Ј:6Ј,2Љ-terpyridine (L1). Method 1. 3-(4-
Anilino)-1,5-bis(2-pyridyl)pentane-1,5-dione (0.30 g, 0.87
3022
J. Chem. Soc., Dalton Trans., 1997, Pages 3011–3028

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(C6), 148.16, 137.48 (C4), 129.05 (Co), 124.32 (C5), 122.03 (C3),
118.47 (C3Ј) and 115.90 (Cm). IR (Nujol mull): 3330w, 1600m,
1585s, 830m, 785s and 728m cmϪ1. UV/VIS (MeOH): λmax/nm
(10Ϫ3 ε/l molϪ1 cmϪ1) 408 (11.3), 326 (16.8), 314 (15.8), 286
(24.4), 234 (22.2) and 204 (35.5).
154.22, 143.92, 131.20, 128.40, 122.85, 116.16 and 115.92. IR
(Nujol mull): 3395w, 1630w, 1590s, 1528w, 1420w, 1310w,
1295w, 1268w, 1243m, 1194m, 1165w, 1100w, 1044w, 1030,
966w, 839s, 781m, 748w and 719w cmϪ1
.
[RuL1 ][PF6]2. Compound L1 (106 mg, 0.33 mmol) was dis-
2
General method for [ML1 ][PF6]2 (M = CoII, CuII, MnII, NiII or
solved in ethanol (120 cm3) at reflux. The complex [Ru(dm-
so)4Cl2] (79 mg, 0.16 mmol) in distilled water (50 cm3) was
slowly added and the resulting solution heated at reflux for 30
min. The solvent was removed in vacuo and the residue dis-
solved in the minimum volume of methanol and purified by gel
permeation chromatography (Sephadex LH20, methanol
eluent). The central bright red band was collected and the
product precipitated by the addition of an excess of aqueous
[NH4][PF6] to afford a red microcrystalline solid (92 mg, 55%)
(Found: C, 47.07; H, 3.56; N, 10.77. Calc. for C42H32F12N8-
P2Ruؒ2H2O: C, 46.85; H, 3.35; N, 10.41%). ES mass spectrum:
m/z 375 (M2ϩ) and 895 ([M ϩ PF6]ϩ). 13C NMR [(CD3)2CO]:
δ 159.5, 156.1, 153.1 (C6), 152.1, 149.2, 138.6 (C4), 129.3 (Co),
128.1 (C5), 125.1 (C3), 123.1, 119.9 (C3Ј) and 115.3 (Cm). IR
(Nujol mull): 3400w, 1600m, 1520w, 1404w, 1184w, 842s, 833s
2
ZnII). Compound L1 (200 mg, 0.62 mmol) was heated to reflux
in methanol (200 cm3) and a solution of the appropriate metal
chloride or metal acetate (0.30 mmol) in methanol (20 cm3) was
added dropwise. After 15 min at reflux, a methanolic solution
of ammonium hexafluorophosphate was added and the solu-
tion allowed to cool whereupon a microcrystalline precipitate
of the appropriate hexafluorophosphate salt was obtained. The
salt was recrystallised from methanol, filtered off and washed
with diethyl ether. Yields were in the range 60–85%.
[CoL1 ][PF6]2. A maroon microcrystalline solid (Found: C,
2
48.31; H, 3.36; N, 10.45. Calc. for C42H32CoF12N8P2ؒ2H2O:
C, 48.79; H, 3.49; N, 10.84%). ES mass spectrum: m/z 353 (M2ϩ
)
and 852 ([M ϩ PF6]ϩ). UV/VIS (acetone): λmax/nm (ε/l molϪ1
cmϪ1) 716 (sh) (200).
[CuL1 ][PF6]2. A green microcrystalline solid (Found: C,
and 784w cmϪ1
.
2
50.11; H, 3.47; N, 11.02. Calc. for C42H32CuF12N8P2: C, 50.32;
H, 3.20; N, 11.18%). ES mass spectrum: m/z 356 (M2ϩ) and 856
([M ϩ PF6]ϩ). UV/VIS (acetone): λmax/nm (ε/l molϪ1 cmϪ1) 685
(100).
[Ru(terpy)L1][PF6]2. The complex [Ru(terpy)Cl3] (272 mg,
0.62 mmol) was reduced by triethylamine in the presence of L1
(200 mg, 0.62 mmol) in ethanol (200 cm3) and water (10 cm3)
heated at reflux for 18 h. The solvent was removed in vacuo and
the residue dissolved in the minimum volume of acetonitrile
and purified by flash chromatography [silica, acetonitrile–
water–saturated KNO3 (aq) 20:2:1 eluent]. The bright red
second band was collected and precipitated by the addition
of an excess of aqueous [NH4][PF6] to afford a red crystalline
solid (320 mg, 55%) (Found: C, 44.86; H, 3.40; N, 9.95%.
Calc. for C36H27F12N7RuؒH2O: C, 44.69; H, 3.00; N, 10.14%).
ES mass spectrum: m/z 329 (M2ϩ) and 804 ([M ϩ PF6]ϩ).
13C NMR [(CD3)2CO]: δ 160.0, 159.7, 157.0, 153.9, 153.7,
150.2, 139.4, 137.0, 130.0, 129.0, 128.8, 125.8, 125.1, 120.6 and
115.9. IR (Nujol mull): 3300w, 1598m, 1408w, 1190w, 838s and
[MnL1 ][PF6]2. A yellow microcrystalline solid (Found: C,
2
50.55; H, 3.43; N, 11.00. Calc. for C42H32F12MnN8P2: C, 50.76;
H, 3.22; N, 11.28%). ES mass spectrum: m/z 352 (M2ϩ) and 851
([M ϩ PF6]ϩ). IR (Nujol mull): 3395w, 1605m, 1017m, 850s,
840s, 821s, 792m and 784m cmϪ1
.
[NiL1 ][PF6]2. A yellow microcrystalline solid (Found: C,
2
48.72; H, 3.40; N, 10.68. Calc. for C42H32F12N8NiP2ؒ2H2O: C,
48.80; H, 3.49; N, 10.84%). ES mass spectrum: m/z 353 (M2ϩ
)
and 851 ([M ϩ PF6]ϩ). IR (Nujol mull): 3400w, 1603s, 1576m,
1554m, 1527m, 1469m, 1190m, 1028m, 1015m, 843s and 792m
cmϪ1. UV/VIS (acetone): λmax/nm (ε/l molϪ1 cmϪ1) 804 (130).
[ZnL1 ][PF6]2. A light yellow microcrystalline solid (Found:
2
765m cmϪ1
.
C, 49.96; H, 3.43; N, 10.85. Calc. for C42H32F12N8P2Zn: C,
49.91; H, 3.17; N, 11.09%). ES mass spectrum: m/z 356 (M2ϩ
)
4Ј-(4-Phthalimidophenyl)-2,2Ј:6Ј,2Љ-terpyridine (L2). Method
1. Compound L1 (129 mg, 0.40 mmol) and phthalic anhydride
(59 mg, 0.40 mmol) were stirred at room temperature in dma
(10 cm3) for 20 h. Acetic anhydride (2 cm3) was added and the
solution heated at 80 ЊC for 5 h. After cooling the product was
precipitated by the addition of water (100 cm3) and filtered off.
The solid was then recrystallised from ethanol to afford dark
yellow needles (130 mg, 72%).
and 857 ([M ϩ PF6]ϩ). 13C NMR [(CD3)2CO]: δ 157.42, 153.58,
150.90, 149.84, 149.22, 142.37, 128.66, 124.31, 123.80, 119.89
and 115.75. IR (Nujol mull): 3395w, 1598s, 1520w, 1190w,
1020m, 1011m, 832s, 790m and 783m cmϪ1
.
[FeL1 ][BF4]2. A solution of [Fe(H2O)6][BF4]2 (186 mg, 0.55
2
mmol) in methanol (10 cm3) was added dropwise to a meth-
anolic solution (150 cm3) of L1 (380 mg, 1.17 mmol) at reflux.
The mixture was heated at reflux for 10 min and allowed to
cool. The resulting precipitate was filtered off and then
recrystallised from methanol as a purple microcrystalline solid
(390 mg, 80%) (Found: C, 55.50; H, 3.97; N, 12.05. Calc. for
C42H32B2F8FeN8ؒ2H2O: C, 55.18; H, 3.94; N, 12.26%). ES mass
spectrum: m/z 352 (M2ϩ) and 791 ([M ϩ BF4]ϩ). ‘13C NMR
[(CD3)2CO]: δ 161.40, 160.00, 154.46, 153.21, 151.87, 139.90,
130.17, 128.57, 124.94, 124.53, 120.52 and 115.89. IR (Nujol
mull): 3490w, 1600s, 1526w, 1415m, 1190m, 1056s, 835w and
Method 2. Compound L1 (120 mg, 0.38 mmol) and phthalic
anhydride (57 mg, 0.38 mmol) were dissolved in nmp (20 cm3)
and heated at 160 ЊC for 16 h. Dropwise addition to a stirring
water solution (200 cm3) resulted in the formation of a precipi-
tate which was filtered off and recrystallised from ethanol to
afford dark yellow needles (125 mg, 74%). M.p. 254–256 ЊC
(Found: C, 76.19; H, 4.37; N, 12.28. Calc. for C29H18N4O2: C,
76.65; H, 3.96; N, 12.33%). EI mass spectrum: m/z 454 (Mϩ)
and 376 (M Ϫ py)ϩ. 1H NMR (CDCl3): δ 8.78 (s, 2 H, H3Ј), 8.74
(d, 2 H, J = 4.6, H6), 8.68 (d, 2 H, J = 8.0, H3), 8.06 (d, 2 H,
J = 8.7, Ho), 7.99 (m, 2 H, HA), 7.89 (td, 2 H, J = 7.7, 1.8, H4),
7.82 (m, 2 H, HB), 7.65 (d, 2 H, J = 8.7, Hm) and 7.36 (ddd, 2 H,
J = 7.7, 5.2, 1.7 Hz, H5). 13C NMR (CDCl3): δ 167.12, 156.14,
156.08, 149.29, 149.16, 138.16, 136.84, 134.49, 132.45, 131.74,
128.02, 126.76, 123.84, 123.82, 121.34 and 118.87. IR (Nujol
mull): 1774w, 1757w, 1740w, 1718s, 1602w, 1582m, 1564w,
1536w, 1510m, 1412w, 1261w, 1220w, 1159w, 1139w, 1114w,
1072w, 1037w, 1012w, 985w, 900w, 889w, 879w, 843w, 829m,
788m cmϪ1
.
[RhL1 ][PF6]3. Compound L1 (200 mg, 0.62 mmol) was dis-
2
solved in hot methanol (200 cm3), RhCl3ؒ3H2O (80 mg, 0.31
mmol) in distilled water (10 cm3) was added dropwise and the
resulting solution heated at reflux for 30 min. The solution was
condensed in vacuo to 50 cm3 and the product was precipitated
by the addition of an excess of aqueous [NH4][PF6]. After filter-
ing the solid, it was recrystallised from acetonitrile–methanol to
afford an orange-brown microcrystalline solid (238 mg, 62%)
(Found: C, 43.76; H, 3.43; N, 10.85. Calc. for C42H32F18N8-
P3Rhؒ2MeCN: C, 43.54; H, 3.00; N, 11.04%). ES mass spec-
trum: m/z 251 (M3ϩ), 448 ([M ϩ PF6]2ϩ) and 1042 ([M ϩ
2PF6]ϩ). 13C NMR [(CD3)2CO]: δ 159.32, 157.13, 154.87, 154.68,
814w, 804w, 790w and 783m cmϪ1
.
4Ј-(4-Benzamidophenyl)-2,2Ј:6Ј,2Љ-terpyridine (L3). Com-
pound L1 (125 mg, 0.39 mmol) was dissolved in a mixture of
nmp (8 cm3) and pyridine (2 cm3). An excess of benzoyl chlor-
J. Chem. Soc., Dalton Trans., 1997, Pages 3011–3028
3023

View Article Online
ide (3 drops) was added and the solution stirred at room tem-
perature for 18 h. The product was precipitated by dropwise
addition to a stirring solution of diethyl ether (150 cm3),
filtered and then recrystallised from methanol to give yellow
feathery needles (151 mg, 92%), m.p. 220–223 ЊC (Found: C,
66.94; H, 5.18; N, 10.77. Calc. for C29H18N4O2ؒ4H2O: C, 67.20;
H, 5.60; N, 11.20%). EI mass spectrum: 428 (Mϩ), 323 {[M Ϫ
C6H5C(O)]ϩ} and 105 [C6H5C(O)]. 1H NMR [(CD3)2SO]: δ
10.56 (br s, 1 H, NH), 8.99 (d, 2 H, J = 7.7, H6), 8.94 (d, 2 H,
J = 8.0, H3), 8.93 (s, 2 H, H3Ј), 8.38 (br t, 2 H, J = 6.7, H4), 8.15
(m, 4 H, Ho and Hm), 8.06 (d, 2 H, HA), 7.83 (br t, 2 H, J = 5.6,
H5), 7.67 (t, 1 H, J = 7.2, HC) and 7.61 (t, 2 H, J = 6.8 Hz, HB).
13C NMR [(CD3)2SO]: δ 166.07, 153.13, 152.16, 150.08, 147.28,
141.29, 141.20, 134.91, 132.08, 131.51, 128.71, 128.01, 127.87,
126.09, 122.99, 120.94 and 119.38. IR (Nujol mull): 3350m (br),
1664m, 1594s, 1397w, 1374w, 1325w, 1295w, 1260 (sh) w, 1237w,
1190w, 1055w, 1018w, 990w, 950w, 888w, 836w, 781m, 705m
20:2:1 eluent] gave a broad purple band which was collected
and precipitated with the addition of an excess of [NH4][BF4]
to give a purple microcrystalline solid (23 mg, 57%) (Found: C,
54.11; H, 4.56; N, 10.72. Calc. for C46H36B2F8FeN8O2ؒ3H2O:
C, 54.38; H, 4.14; N, 11.03%). ES mass spectrum: m/z 394
(M2ϩ) and 877 ([M ϩ BF4]ϩ). 13C NMR [(CD3)2SO]: δ 169.08,
159.93, 158.08, 152.95, 148.68, 141.90, 138.85, 130.17, 128.55,
127.69, 124.12, 120.48, 119.42 and 24.39. 1H NMR
[(CD3)2CO]: δ 9.55 (s, 2 H, H3Ј), 9.52 (br s, NH), 8.97 (d, 2 H,
J = 7.9, H3), 8.38 (d, 2 H, J = 8.7, Ho), 8.02 (m, 4 H, Hm and
H4), 7.53 (d, 2 H, J = 5.1, H6), 7.21 (t, 2 H, J = 6.7 Hz, H5)
and 2.78 (s, 3 H, CH3). IR (Nujol mull): 3400w, 1692m,
1596m, 1521m, 1412m, 1320w, 1304w, 1248w, 1190w, 1060s,
834w and 790m cmϪ1
.
[Ru(terpy)L2][PF6]2. The complex [Ru(terpy)L1][PF6]2 (60
mg, 0.06 mmol) and phthalic anhydride (20 mg, 0.13 mmol)
were dissolved in nmp (15 cm3) and stirred at 145 ЊC for 20 h.
After cooling it was precipitated by dropwise addition to a
stirring solution of diethyl ether (200 cm3). The solid was fil-
tered off, dissolved in the minimum volume of acetonitrile and
purified by flash chromatography [silica, acetonitrile–water–
saturated KNO3 (aq) 20:2:1 eluent]. The first and second
and 655w cmϪ1
[FeL2 ][BF4]2. The complex [FeL1 ][BF4]2 (114 mg, 0.13
.
2
2
mmol) and phthalic anhydride (42 mg, 0.27 mmol) were
dissolved in dma (10 cm3) and stirred at room temperature for
18 h. Acetic anhydride (4 cm3) and pyridine (2 cm3) were
added and the solution heated to 80 ЊC for 5 h. After cooling it
was precipitated by dropwise addition to a stirring solution of
diethyl ether (200 cm3). The solid was filtered off, dissolved in
the minimum volume of acetonitrile and purified by flash
chromatography [silica, acetonitrile–water–saturated KNO3
(aq) 20:2:1 eluent]. The initial light purple band eluted was
1
bands were identified by H NMR spectroscopy as unchanged
[Ru(terpy)L1]2ϩ (9% yield) and the acetamido complex
[Ru(terpy)L4]2ϩ (8% yield) respectively. The third dark red band
was collected and the product precipitated by the addition
of an excess of aqueous [NH4][PF6] and recrystallised from
aqueous acetonitrile to afford a red powder (38 mg, 55%)
(Found: C, 48.59; H, 3.06; N, 9.10. Calc. for C44H29F12N7-
O2P2Ruؒ0.5H2O: C, 48.55; H, 2.94; N, 9.01%). ES mass spec-
trum: m/z 394 (M2ϩ) and 934 ([M ϩ PF6]ϩ). 13C NMR
[(CD3)2CO]: δ 168.19, 159.7, 159.6, 157.1, 156.8, 153.9, 153.8,
148.9, 139.53, 139.48, 137.4, 136.1, 133.3, 129.4, 129.02, 129.00,
126.0, 125.8, 125.2, 124.7 and 122.9. IR (Nujol mull): 1780s,
1760s, 1742s, 1719m, 1517w, 1410w, 1220w, 1158w, 1130w,
1
identified by H NMR spectroscopy as a 1:3 mixture of unre-
acted [FeL1 ]2ϩ and the acetamidophenylterpyridyl complex,
2
[FeL4 ]2ϩ. The broad second purple band was collected and the
2
product precipitated with the addition of an excess of aqueous
[NH4][BF4] to afford a purple powder (85 mg, 58%) (Found:
C, 61.56; H, 3.88; N, 11.49. Calc. for C58H36B2F8FeN8O4ؒ
2CH3CN: C, 61.01; H, 3.44; N, 11.48%). ES mass spectrum: m/z
482 (M2ϩ). 13C NMR [(CD3)2SO]: δ 167.10, 160.14, 158.02,
156.02, 148.51, 138.98, 135.57, 134.17, 131.77, 128.49, 128.10,
127.79, 124.26, 123.75 and 121.45. IR (Nujol mull): 1720m,
1070w and 836s cmϪ1
.
[Ru(terpy)L3][PF6]2. The complex [Ru(terpy)L1][PF6]2 (53
mg, 0.06 mmol) was dissolved in freshly distilled acetonitrile
(35 cm3), benzoyl chloride (4 drops) and pyridine (2 cm3) were
added and the solution heated at reflux for 6 h. During this
period a red solid precipitated. After cooling this solid was
filtered off and washed with diethyl ether until all traces of
pyridine were removed. The product was recrystallised from
methanol to give a red microcrystalline solid which was filtered
off and washed with diethyl ether. A second portion of the
product was obtained from the initial filtrate by condensing
the solution in vacuo, dissolving the residue in the minimum
volume of acetonitrile and purified by flash chromatography
[silica, acetonitrile–water–saturated KNO3 (aq) 20:2:1 eluent].
The bright red second band was collected and the product
precipitated by the addition of an excess of aqueous
[NH4][PF6] to afford a red powder (40 mg, 68%) (Found: C,
49.16; H, 3.32; N, 9.04. Calc. for C43H31F12N7OP2Ru: C, 49.02;
H, 2.94; N, 9.31%). ES mass spectrum: m/z 382 (M2ϩ) and 907
([M ϩ PF6]ϩ). 13C NMR [(CD3)2SO]: δ 166.18, 158.24, 157.94,
155.15, 155.01, 152.34, 152.24, 149.81, 146.70, 141.59, 138.27,
134.84, 132.11, 130.91, 128.71, 128.39, 127.99, 125.03, 124.73,
124.19, 120.74 and 120.64. IR (Nujol mull): 3360w (br) 1658m,
1595m, 1518w, 1238w, 1190w, 1024w, 882w, 840m, 778w and
1596w, 1520w, 1415w, 1191w, 1060s, 842w and 786m cmϪ1
[FeL3 ][BF4]2. The complex [FeL1 ][BF4]2 (97 mg, 0.12 mmol)
.
2
2
was dissolved in acetonitrile (50 cm3), pyridine (4 cm3) and an
excess of benzoyl chloride (5 drops) were added and the solu-
tion heated at reflux for 16 h. Over this period a purple solid
precipitated and after cooling it was filtered off and washed
with water and diethyl ether. The solid was recrystallised from
methanol to afford a purple powder (100 mg, 80%) (Found: C,
57.71; H, 4.15; N, 9.70. Calc. for C56H40B2F8FeN8O2ؒ4H2O: C,
58.06; H, 4.15; N, 9.68%). ES mass spectrum: m/z 456 (M2ϩ
)
and 1000 ([M ϩ BF4]ϩ). 13C NMR [(CD3)2SO]: δ 166.57,
160.25, 158.35, 153.16, 149.01, 141.87, 139.23, 134.97, 132.50,
131.22, 129.08, 128.80, 128.22, 128.03, 124.49, 121.10 and
120.90. IR (Nujol mull): 3380w, 1665m, 1590m, 1517m, 1190w,
1050w and 832w cmϪ1
.
[FeL4 ][BF4]2. Method 1. The complex [FeL1 ][BF4]2 (60 mg,
2
2
0.07 mmol) and an excess of acetyl chloride were heated at
reflux in acetonitrile (50 cm3) and pyridine (2 cm3) for 6 h. The
purple solid that precipitated from the solution during this
period was filtered off and recrystallised from methanol to give
a purple microcrystalline solid (48 mg, 73%).
750m cmϪ1
.
Method 2. The complex [FeL1 ][BF4]2 (35 mg, 0.04 mmol),
2
acetic anhydride (4 cm3) and pyridine (2 cm3) were stirred in
dma (10 cm3) at room temperature for 1 h and then heated at
80 ЊC for 3 h. Dropwise addition of the solution to diethyl
[Ru(terpy)L4][PF6]2. Method 1. The complex [Ru(terpy)-
L1][PF6]2 (100 mg, 0.1 mmol) was dissolved in dma (10 cm3)
and stirred with acetic anhydride (4 cm3) and pyridine (2 cm3),
the solution heated to 80 ЊC for 3 h and then stirred at room
temperature for 16 h. The products were precipitated by drop-
wise addition to a stirring solution of diethyl ether (200 cm3)
and filtered off. The solid was dissolved in the minimum volume
of acetonitrile and purified by flash chromatography [silica,
1
ether (200 cm3) resulted in a purple precipitate (the H NMR
spectrum showed quantitative conversion into the acetamide
complex) which was filtered off and then dissolved in the
minimum volume of acetonitrile. Purification by flash chroma-
tography [silica, acetonitrile–water–saturated KNO3 (aq)
3024
J. Chem. Soc., Dalton Trans., 1997, Pages 3011–3028

View Article Online
acetonitrile–water–saturated KNO3 (aq) 20:2:1 eluent]. The
initial red band was collected and the product precipitated
by the addition of an excess of aqueous [NH4][PF6] to afford
a red microcrystalline solid (55 mg, 50%) (Found: C, 44.50;
H, 3.46; N, 9.45. Calc. for C38H29F12N7OP2Ruؒ2H2O: C, 44.44;
H, 3.22; N, 9.55%). ES mass spectrum: m/z 357 (M2ϩ) and
860 ([M ϩ PF6]ϩ). 13C NMR [(CD3)2CO]: δ 169.83, 159.83,
159.64, 158.92, 153.89, 153.82, 149.23, 143.20, 139.48, 137.29,
132.04, 129.50, 129.02, 128.96, 125.95, 125.78, 125.16, 122.01,
120.82, 120.74 and 24.78. IR (Nujol mull): 3400w, 1676m,
1603m, 1592m, 1520m, 1190w, 1159w, 1025w, 840s and
8.86 (s, 4 H, H3Ј), 8.29 (t, 4 H, J = 6.7, H5), 8.01 (d, 4 H, J = 8.2,
Ho), 7.87 (d, 4 H, J = 8.7 Hz, Hm), 2.85 (br s, 4 H, CH2) and 2.11
(br s, 4 H, CH2). 13C NMR (CF3CO2D): δ 163.89, 141.35,
135.13, 134.02, 133.62, 129.12, 125.15, 119.92, 114.92, 114.85,
111.58, 110.17, 109.82, 22.51 and 11.54. IR (Nujol mull):
3320w (br), 1655m, 1590m, 1575s, 1558w, 1510s, 1405w, 1305w,
1290w, 1250w, 1218w, 1178w, 1105w, 1062w, 1026w, 978w,
940w, 875w, 822m, 778s and 735w cmϪ1
.
[(terpy)RuL5Ru(terpy)][PF6]4. Method (a). (i) The complex
[Ru(terpy)Cl3] (163 mg, 0.37 mmol) and AgSbF6 (381 mg, 1.11
mmol) were heated at reflux for 3 h in acetone (60 cm3). The
reaction mixture was filtered to remove the precipitated AgCl
and the filtrate added to dmf (30 cm3). The acetone was
removed in vacuo and the dmf solution added to a solution of
L5 (160 mg, 0.18 mmol) in dmf (350 cm3) and heated at reflux
under N2 for 5 h. The reaction mixture was filtered to remove
unreacted L5 and then dmf (300 cm3) was removed by distil-
lation and the products precipitated by the addition of an
excess of [NH4][PF6] in water (50 cm3). The solid was filtered
off, dissolved in acetonitrile and purified by flash chroma-
tography [silica, acetonitrile–water–saturated KNO3 (aq)
20:2:1 eluent]. The first fraction was identified as [Ru-
(terpy)2]2ϩ (15% yield), while the second band was a mixture of
complexes which were not separated. The broad slow-moving
third band was collected and precipitated with an excess of
aqueous [NH4][PF6]. The solid was filtered off and recrystal-
lised from aqueous acetonitrile to give a red microcrystalline
solid (123 mg, 32%).
765m cmϪ1
.
N,NЈ-Bis[4-(2,2Ј:6Ј,2Љ-terpyridin-4Ј-yl)phenyl]pyromellit-
imide (L5). Pyromellitic dianhydride (74 mg, 0.34 mmol) was
slowly added to L1 (220 mg, 0.68 mmol) dissolved in dma (8
cm3) and stirred at room temperature for 18 h. At this point the
bis(amic acid), aa, can be precipitated by addition of diethyl
ether, m.p. >350 ЊC (Found: C, 66.70; H, 4.43; N, 11.36. Calc.
for C52H34N8O6ؒ4H2O: C, 66.52; H, 4.47; N, 11.94%). 1H NMR
[(CD3)2SO]: δ 10.85 (s, 2 H, OH), 8.78 (br d, 4 H, H6), 8.75 (s, 4
H, H3Ј), 8.69 (d, 4 H, H3), 8.00 (m, 14 H, Ho, Hm, H4 and Hp)
and 7.54 (br t, 4 H, H5). If instead a mixture of acetic anhydride
(8 cm3) and pyridine (4 cm3) was added and the solution stirred,
the product precipitated. After 1 h the precipitated solid was
filtered off, boiled in methanol and then filtered whilst hot,
washed with diethyl ether and dried to give a dull yellow pow-
der (258 mg, 91%), m.p. >350 ЊC (Found: C, 70.88; H, 4.02;
N, 12.49. Calc. for C52H30N8O4ؒ3H2O: C, 70.59; H, 4.07; N,
12.67%). EI mass spectrum: m/z 830 (Mϩ). 1H NMR
(CF3CO2D): δ 9.23 (d, 4 H, J = 5.4, H6), 9.03 (d, 4 H, J = 8.3,
H3), 8.93 (m, 8 H, H4 and H3Ј), 8.77 (s, 2 H, Hp), 8.32 (t, 4 H,
J = 7.0, H5), 8.18 (d, 4 H, J = 8.3, Ho) and 7.88 (d, 4 H, J = 8.2
Hz, Hm). 13C NMR (CF3CO2D): δ 190.63, 153.65, 141.14,
135.21, 134.35, 133.59, 129.34, 124.21, 123.24, 119.68, 115.37,
115.05, 114.83, 111.70 and 110.30. IR (Nujol mull): 1778w,
1740s, 1590m, 1570w, 1548w, 1520m, 1198w, 1038w, 810m,
(ii) The complex [Ru(terpy)Cl3] (100 mg, 0.23 mmol) and L5
(92 mg, 0.11 mmol) in ethane-1,2-diol (20 cm3) were heated at
reflux for 20 min. The products were precipitated by the add-
ition of an excess of [NH4][PF6] in water (50 cm3). The solid
was filtered off, dissolved in acetonitrile and purified by flash
chromatography [silica, acetonitrile–water–saturated KNO3
(aq) 20:2:1 eluent]. The first fraction was identified as
[Ru(terpy)2]2ϩ (8% yield), while the second band was a mixture
of complexes which were not separated. The broad slow-
moving third band was collected and precipitated with an
excess of aqueous [NH4][PF6]. The solid was filtered off and
recrystallised from aqueous acetonitrile to give a red micro-
crystalline solid (155 mg, 44%).
785m and 730m cmϪ1
.
N,NЈ-Bis[4-(2,2Ј:6Ј,2Љ-terpyridin-4Ј-yl)phenyl]terephthal-
amide (L6). Terephthaloyl chloride was added to L1 (300 mg,
0.93 mmol) dissolved in dma (25 ml) and pyridine (8 cm3) with
stirring at room temperature. A light yellow solid began to pre-
cipitate almost immediately. The mixture was stirred for 2 h and
then the solid was filtered off and washed with diethyl ether
to give a light yellow powder. A second portion of the product
was obtained by precipitation upon addition of the filtrate to
methanol (150 cm3). This solid was filtered off, washed with
methanol and diethyl ether to afford a light yellow powder (255
mg, 70%), m.p. >350 ЊC (Found: C, 73.18; H, 5.39; N, 14.14.
Calc. for C50H38N8O2ؒ1.5H2O: C, 73.38; H, 5.22; N, 14.27%). 1H
NMR (CF3CO2D): δ 9.21 (d, 4 H, J = 5.9, H6), 9.03 (d, 4 H,
J = 8.5, H3), 8.91 (m, 8 H, H4 and H3Ј), 8.30 (t, 4 H, J = 6.5, H5),
8.28 (s, 4 H, Hp), 8.09 (d, 4 H, J = 9.0, Ho) and 8.03 (d, 4 H,
J = 8.6 Hz, Hm). 13C NMR (CF3CO2D): δ 184.25, 152.88,
137.73, 131.48, 130.40, 129.97, 125.49, 122.10, 116.17, 111.48,
107.92, 106.63 and 106.14. IR (Nujol mull): 3250w, 1670m,
1598s, 1582w, 1516m, 1412w, 1323m, 1298w, 1257m, 1185w,
1104w, 1070w, 1035w, 1010w, 984w, 878w, 863w, 828m and
Method (b). The complex [Ru(terpy)L1][PF6]2 (165 mg, 0.16
mmol) and pyromellitic dianhydride (19 mg, 0.08 mmol) were
stirred at room temperature for 18 h in dma (10 cm3). A mixture
of pyridine (2 cm3) and acetic anhydride (4 cm3) was added and
the solution heated to 80 ЊC for 3 h. The products were pre-
cipitated by dropwise addition to diethyl ether (250 cm3) and
the solid filtered off and dissolved in acetonitrile. Purification
by flash chromatography [silica, acetonitrile–water–saturated
KNO3 (aq) 20:2:1 eluent] led to three bands separating on the
column. The first band was identified (1H NMR and mass
spectroscopies) as the acetamidophenylterpyridine complex,
[Ru(terpy)L4]2ϩ (24% yield) and the second band contained a
mixture of complexes which were not separated. The third band
was collected and precipitated with an excess of aqueous
[NH4][PF6]. The solid was filtered off and recrystallised from
aqueous acetonitrile to give a red microcrystalline solid (72 mg,
40%) (Found: C, 47.13; H, 3.05; N, 8.50. Calc. for C82H52F24-
N14O4P4Ru2: C, 47.37; H, 2.50; N, 9.44%). ES mass spectrum:
m/z 375 (M4ϩ), 548 ([M ϩ PF6]3ϩ) and 896 ([M ϩ 2PF6]2ϩ). 13C
NMR [(CD3)2SO]: δ 165.63, 158.19, 157.98, 155.36, 154.96,
152.40, 146.25, 138.36, 137.47, 136.17, 133.50, 129.08, 128.54,
128.40, 127.95, 125.47, 125.01, 124.77, 124.23, 121.56 and
118.38. IR (Nujol mull): 1775w, 1720m, 1600w, 1510w, 1404w,
782m cmϪ1
.
N,NЈ-Bis[4-(2,2Ј:6Ј,2Љ-terpyridin-4Ј-yl)phenyl]adipamide
(L7). Adipoyl chloride (47 mg, 0.25 mmol) was added to L1 (166
mg, 0.51 mmol) dissolved in dma (15 cm3) and pyridine (4 cm3)
at 120 ЊC and the solution was stirred for 2 h. After cooling the
resulting precipitate was filtered off and washed with methanol
and diethyl ether to give a cream flaky solid (143 mg, 73%),
m.p. >350 ЊC (Found: C, 69.52; H, 5.48; N, 13.70. Calc. for
C48H38N8O2ؒ4H2O: C, 69.40; H, 5.54; N, 13.49%). EI mass spec-
1282w, 1240w, 1198w, 1025w and 835s cmϪ1
.
[(terpy)RuL6Ru(terpy)][PF6]4. Method (a). The complex
[Ru(terpy)Cl3] (170 mg, 0.39 mmol) and AgSbF6 (398 mg, 1.16
mmol) were heated at reflux for 3 h in acetone (60 cm3). The
1
trum: m/z 766 (Mϩ). H NMR (CF3CO2D): δ 9.19 (d, 4 H,
J = 5.6, H6), 9.00 (d, 4 H, J = 7.7, H3), 8.89 (t, 4 H, J = 8.2, H4),
J. Chem. Soc., Dalton Trans., 1997, Pages 3011–3028
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reaction mixture was filtered to remove the precipitated AgCl
and added to dmf (30 cm3). The acetone was removed in vacuo
and the dmf solution added to a solution of L6 (150 mg, 0.19
mmol) in dmf (400 cm3) and heated at reflux for 5 h. The dmf
(250 cm3) was removed by distillation and the products precipi-
tated by the addition of an excess of [NH4][PF6] in water (100
cm3). The solid was filtered off, dissolved in acetonitrile and
purified by flash chromatography [silica, acetonitrile–water–
saturated KNO3 (aq) 20:2:1 eluent]. The broad slow-moving
third band was collected and precipitated with an excess of
aqueous [NH4][PF6]. The solid was filtered off and recrystal-
lised from aqueous acetonitrile to give a red microcrystalline
solid (175 mg, 48%).
mmol) were stirred at room temperature in dma (20 cm3) for 16
h and then heated at reflux for 3 h. The reaction mixture was
cooled, an excess of acetyl chloride (5 drops) added and the
solution heated at reflux for 1 h. After cooling the reaction
mixture was added to an aqueous solution (200 cm3) containing
an excess of NH4BF4 to precipitate the polymer and the mix-
ture stirred for 2 h. The solid was filtered off and washed with
methanol and acetone repeatedly to remove lower-molecular-
weight oligomers. The solid was placed in a flask containing
methanol (200 cm3), heated at reflux for 20 min and then
filtered hot. A purple powder was obtained (221 mg, 83%).
An analytical sample was obtained by dissolving a sample in
dmf and precipitating by dropwise addition to rapidly stirred
dichloromethane (Found: C, 54.85; H, 3.70; N, 9.97. Calc.
for C52H30B2F8FeN8O4ؒ4H2O: C, 55.15; H, 3.36; N, 9.99%).
Method (b). The complex [Ru(terpy)L1][PF6]2 (101 mg, 0.11
mmol) and terephthaloyl chloride (21.6 mg, 0.05 mmol) were
heated at 180 ЊC for 16 h in a dma (10 cm3)–pyridine (5 cm3)
mixture. After cooling the mixture was precipitated by drop-
wise addition to diethyl ether (250 cm3) and the solid filtered off
and dissolved in acetonitrile. The first and second bands were
identified as [Ru(terpy)L1]2ϩ (3% yield) and [Ru(terpy)2]2ϩ (10%
yield), respectively. Purification by flash chromatography [silica,
acetonitrile–water–saturated KNO3 (aq) 20:2:1 eluent]. The
third band was collected and precipitated with an excess of
aqueous [NH4][PF4]. The solid was filtered off and recrystal-
lised from aqueous acetonitrile to give a red microcrystalline
solid (49 mg, 44%) (Found: C, 47.70; H, 2.93; N, 9.95. Calc. for
C80H56F24N14O2P4Ru2ؒCH3CN: C, 47.60; H, 2.85; N, 10.15%).
ES mass spectrum: m/z 362 (M4ϩ), 531 ([M ϩ PF6]3ϩ) and 869
([M ϩ 2PF6]2ϩ). 13C NMR [(CD3)2SO]: δ 165.39, 158.25,
157.98, 155.20, 155.01, 152.37, 146.58, 141.35, 138.28, 137.68,
136.01, 131.24, 128.36, 128.19, 127.95, 124.99, 124.74, 124.20,
120.86 and 120.67. IR (Nujol mull): 3420w, 1648w, 1595m,
1520w, 1329w, 1284w, 1180m, 1080m, 846m, 836s, 827s, 783m
MALDI-TOF mass spectrum: m/z 1716 ([FeL5 ]ϩ) and 833
2
1
([L5 ϩ 3]ϩ). H NMR: (CD3CO2D) δ 9.32 (br s, 4 H, H3Ј), 9.0–
8.2 (m, 10 H, H3, Ho and Hp), 8.01 (br s, 8 H, H4 and Hm) and
7.20 (br d, 8 H, H6 and H5); [(CD3)2SO] δ 9.84 (br s, 4 H, H3Ј),
9.16 (br s, 4 H, H3), 9.0–8.5 (m, 6 H, Ho and Hp), 8.10 (m, 8 H,
H4 and Hm), 7.35 (m, 8 H, H6 and H5). IR (Nujol mull): 1775w,
1723s, 1600m, 1515w, 1411w, 1240w, 1050s (br), 866w, 830w,
785m, 750w and 717w cmϪ1
.
Method (a). Compound L5 (150 mg, 0.18 mmol) was sus-
pended in dmf (500 cm3), FeCl2ؒ4H2O (36 mg, 0.18 mmol)
added and the mixture heated at reflux for 18 h. The polymer
was isolated as above (98 mg, 51%). This sample gave identical
infrared, UV/VIS and 1H NMR spectra to the sample prepared
by route (b).
[(FeL6)n][BF4]2n. Method (b). The complex [FeL1 ][BF4]2 (212
2
mg, 0.25 mmol) and terephthaloyl chloride (51 mg, 0.25 mmol)
were heated at reflux in dma (20 cm3) and pyridine (4 cm3) for
18 h. After cooling the reaction mixture was added to an aque-
ous solution containing an excess of [NH4][BF4] (200 cm3) to
precipitate the polymer and the mixture stirred for 2 h. The
solid was filtered off and washed with methanol and acetone
repeatedly to remove lower-molecular-weight oligomers. The
solid was placed in a flask containing methanol (200 cm3),
refluxed for 20 min and then filtered whilst hot. A purple
powder was obtained (150 mg, 60%). An analytical sample
was obtained by dissolving the purple powder in warm dmf
and precipitating by dropwise addition to rapidly stirred di-
chloromethane (Found: C, 55.68; H, 4.10; N, 9.66. Calc. for
C50H34B2F8FeN8O2ؒ4H2O: C, 55.59; H, 3.89; N, 10.38%).
MALDI-TOF mass spectrum: m/z 1613 ([FeL62 ϩ 1]ϩ) and 780
[(L6)ϩ]. 1H NMR: (CD3CO2D) δ 8.31 (br s, 4 H, H3Ј), 8.20 (br s,
8 H, H3 and Ho) and 7.8–7.2 (m, 20 H, Hp, Hm, H4, H6 and H5);
[(CD3)2SO] δ 10.95 (br s, 2 H, NH), 9.74 (br s, 4 H, H3Ј), 9.13 (br
s, 4 H, H3), 8.75 (m, 4 H, Ho), 8.5–7.9 (m, 12 H, Hp, H4 and Hm)
and 7.30 (m, 8 H, H6 and H5). IR (Nujol mull): 3360w (br),
1658m, 1590m, 1510w, 1320w, 1303w, 1240w, 1185w, 1050s (br),
and 768m cmϪ1
.
[(terpy)RuL7Ru(terpy)][PF6]4. Method (a). The complex
[Ru(terpy)Cl3] (88 mg, 0.20 mmol) and L7 (76 mg, 0.10 mmol)
were heated at reflux for 15 min in ethane-1,2-diol (15 cm3).
After cooling the products were precipitated by the addition
of an excess of [NH4][PF6] in water (20 cm3). The solid was
filtered off, dissolved in acetonitrile and purified by flash chrom-
atography [silica, acetonitrile–water–saturated KNO3 (aq)
20:2:1 eluent]. The broad slow-moving third band was col-
lected and precipitated with an excess of aqueous [NH4][PF6].
The solid was filtered off and recrystallised from aqueous
acetonitrile to give a red microcrystalline solid (82 mg, 41%).
Method (b). The complex [Ru(terpy)L1][PF6]2 (250 mg, 0.26
mmol) and adipoyl chloride (24 mg, 0.13 mmol) were heated at
reflux for 20 h in dmf (15 cm3) and pyridine (2 cm3). After
cooling the mixture was precipitated by dropwise addition to
diethyl ether (250 cm3) and the solid filtered off and dissolved in
acetonitrile. Purification by flash chromatography [silica,
acetonitrile–water–saturated KNO3 (aq) 20:2:1 eluent]. The
third band was collected (the first, second and fourth fractions
were collected and identified, selected data are given below) and
precipitated with an excess of aqueous [NH4][PF6]. The solid
was filtered off and recrystallised from aqueous acetonitrile to
give a red microcrystalline solid (78 mg, 30%) (Found: C, 44.08;
H, 3.56; N, 9.00. Calc. for C78H68F24N14O2P4Ru2ؒ6H2O: C,
44.27; H, 3.41; N, 9.27%). ES mass spectrum: m/z 357 (M4ϩ),
983w, 830w, 784m, 749w and 716m cmϪ1
.
[(FeL7)n][BF4]2n. Method (b). The complex [FeL1 ][BF4]2 (209
2
mg, 0.25 mmol), adipoyl chloride (50.7 mg, 0.25 mmol) and
pyridine (4 cm3) were heated at reflux in dma (20 cm3) for 18 h.
An excess of acetyl chloride was added and the reaction mix-
ture refluxed for 1 h to end-cap the polymer chains. After cool-
ing the mixture was added to an aqueous solution of NH4BF4
(200 cm3) and stirred for 2 h. The solid was filtered off and
washed repeatedly with water, acetone and methanol to remove
low-molecular-weight oligomers. The solid was suspended in
acetone–methanol (1:1) solution and boiled for 15 min. A pur-
ple powder was filtered off (130 mg, 52%). An analytical sample
was obtained by dissolving a sample of it in dmf and precipitat-
ing by dropwise addition to rapidly stirred dichloromethane
(Found: C, 55.04; H, 4.52; N, 10.78. Calc. for C48H38B2F8-
FeN8O2ؒ3H2O: C, 55.33; H, 4.23; N, 10.76%). MALDI-TOF
)
523 ([M ϩ PF6]3ϩ and 859 ([M ϩ 2PF6]2ϩ). 13C NMR
[(CD3)2SO]: δ 171.83, 158.22, 157.98, 155.12, 155.01, 152.32,
146.66, 141.64, 138.22, 135.96, 130.32, 128.41, 127.90, 124.93,
124.72, 124.18, 120.48, 119.49, 36.60 and 24.98. IR (Nujol
mull): 3400w (br), 1665w, 1600m, 1520w, 1505w, 1402w, 1300w,
1026w and 839s cmϪ1
.
[(FeL5)n][BF4]2n. Method (b). The complex [FeL1 ][BF4]2 (219
2
mg, 0.25 mmol) and pyromellitic dianhydride (54 mg, 0.25
mass spectrum: m/z 1589 ([FeL7 ]ϩ) and 767 ([L7 ϩ 1]ϩ). 1H
2
3026
J. Chem. Soc., Dalton Trans., 1997, Pages 3011–3028

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NMR: (CD3CO2D) δ 8.5–8.0 (m, 16 H, H3Ј, H3, Ho and H4),
7.58 (br s, 4 H, Hm), 7.29 (br s, 4 H, H6), 7.17 (br s, 4 H, H5), 2.15
(br s, 4 H, CH2) and 1.39 (br s, 4 H, CH2); [(CD3)2SO]: δ 10.48
(br s, 2 H, NH), 9.70 (br s, 4 H, H3Ј), 9.09 (br s, 4 H, H3), 8.61
(br s, 4 H, Ho), 8.08 (br s, 8 H, H4 and Hm), 7.23 (m, 4 H, H5),
≈2.5 (br s, 4 H, CH2) and 1.84 (br s, 4 H, CH2). IR (Nujol mull):
3350w (br), 1678m, 1594s, 1520m, 1403w, 1303w, 1240w, 1189w,
excess of aqueous ammonium hexafluorophosphate was added
and the solution volume condensed in vacuo to 400 cm3. The
solution was cooled and the resulting solid filtered off and
washed with diethyl ether. The solid was then dissolved in
acetonitrile and purified by flash chromatography [silica,
acetonitrile–water–saturated KNO3 (aq) 20:2:1 eluent]. The
initial reddish band was collected and precipitated by the add-
ition of an excess of aqueous ammonium hexafluorophosphate
and recrystallised from acetonitrile–water (1:1) to give a red-
purple microcrystalline solid (120 mg, 51%) (Found: C, 53.22;
H, 3.64; N, 8.55. Calc. for C58H44F12N8O6P2Zn: C, 53.40; H,
3.38; N, 8.59%). ES mass spectrum: m/z 507 (M2ϩ). 13C NMR
[(CD3)2CO]: δ 183.43, 180.14, 160.25, 154.42, 149.64, 147.93,
144.23, 141.53, 141.27, 131.51, 129.45, 127.89, 123.69, 123.38,
120.83, 104.80, 99.66, 65.57 and 14.01. IR (Nujol mull): 3300w,
1660m, 1640w, 1590s, 1528m, 1239w, 1187m, 1050w, 1020m,
1055s (br), 880w, 834m and 787m cmϪ1
.
4Ј-[N-(5-Ethoxy-1,4-benzoquinonyl)-4-anilino]-2,2Ј:6Ј,2Љ-
terpyridine (L9). 1,4-Benzoquinone (0.69 g, 6.27 mmol) dissolved
in ethanol (30 cm3) was added dropwise to L1 (2.03 g, 6.27 mmol)
in ethanol (450 cm3) at reflux. The reaction mixture was heated
at reflux for 18 h. After cooling a small quantity of light green
precipitate was filtered from the solution. The filtrate was con-
densed in vacuo to ≈150 cm3 and the solid filtered off and
washed with diethyl ether. Recrystallisation from ethanol
afforded a dark red-brown solid (0.97 g, 34%), m.p. 274–278 ЊC
(Found: C, 73.29; H, 4.69; N, 11.84. Calc. for C29H22N4O3: C,
73.42; H, 4.64; N, 11.81%). EI mass spectrum: m/z 474 (Mϩ),
459 ([M Ϫ CH3]ϩ) and 431 ([M Ϫ OEt]ϩ). 1H NMR [(CD3)2SO]:
δ 9.35 (s, 1 H, NH), 8.79 (d, 2 H, J = 4.9 Hz, H6), 8.75 (s, 2 H,
H3Ј), 8.71 (d, 2 H, J = 7.9, H3), 8.05 (m, 4 H, Ho and H4), 7.59
(m, 4 H, H5 and Hm), 6.11 (s, 1 H, HQ), 6.03 (s, 1 H, HQ), 4.11
(q, 2 H, J = 7.0, CH2) and 1.39 (t, 3 H, J = 6.9 Hz, CH3). 13C-
{1H} NMR [(CD3)2SO]: δ 183.42, 179.91, 160.39, 155.93,
155.17, 149.57, 148.91, 144.45, 139.58, 137.70, 128.06, 124.77,
123.75, 121.16, 117.85, 115.83, 104.66, 98.78, 65.48 and 13.99.
IR (Nujol mull): 3318w, 1660s, 1600m, 1576s, 1532m, 1389m,
1012m, 1000w, 905w and 838s cmϪ1
.
[Ru(terpy)L9][PF6]2. Compound L9 (200 mg, 0.42 mmol) was
dissolved in ethanol (700 cm3) heated at reflux, [Ru(terpy)Cl3]
(186 mg, 0.40 mmol) in water (50 cm3) was added and the solu-
tion washeated at refluxfor 3h. Thesolution wasfiltered through
Celite, the solvent removed in vacuo, and the residue dissolved in
acetonitrile and purified by chromatography [silica, acetonitrile–
water–saturated KNO3 (aq) 20:2:1 eluent]. The initial bright red
band was collected and precipitated by the addition of an excess
of aqueous ammonium hexafluorophosphate and recrystallised
from acetonitrile–water (1:1) to give a red microcrystalline solid
(209 mg, 45%) (Found: C, 47.00; H, 3.45; N, 8.53. Calc. for
C36H27F12N7O3P2RuؒH2O: C, 47.28; H, 3.13; N, 8.78). ES mass
spectrum: m/z 404 (M2ϩ) and 954 ([M ϩ PF6]ϩ). 13C-{1H} NMR
[(CD3)2CO]: δ 186.59, 183.52, 160.39, 158.22, 157.97, 155.22,
155.00, 154.73, 152.33, 146.49, 138.28, 136.02, 132.25, 128.86,
127.94, 124.98, 124.72, 124.18, 123.13, 120.98, 119.53, 104.76,
99.26, 65.52 and 14.04. IR (Nujol mull): 3285w, 1665m, 1590s,
1185m, 782s and 722m cmϪ1
.
[CoL9 ][PF6]2. The compound L9 (150 mg, 0.32 mmol) was
2
dissolved in ethanol (700 cm3) heated at reflux and CoCl2ؒ6H2O
(38 mg, 0.16 mmol) in ethanol (10 cm3) was added. After 30 min
an excess of aqueous ammonium hexafluorophosphate was
added and the solution volume reduced to 400 cm3. The solu-
tion was cooled and the resulting solid filtered off and washed
with diethyl ether. The solid was then dissolved in acetonitrile
and purified by chromatography [silica, acetonitrile–water–
saturated KNO3 (aq) 20:2:1 eluent]. The initial broad maroon
band was collected and precipitated by the addition of an
excess of aqueous ammonium hexafluorophosphate and
recrystallised from acetonitrile–water (1:1) to give a maroon
microcrystalline solid (135 mg, 65%) (Found: C, 50.75; H, 3.91;
N, 8.02. Calc. for C58H44CoF12N8O6P2ؒ4H2O: C, 50.84; H, 3.80;
N, 8.18%). ES mass spectrum: 504 (M2ϩ). IR (Nujol mull):
1524m, 1240m, 840s and 790m cmϪ1
.
X-Ray crystallography
Crystal data. For L1. C21H16N4, M 324.4, monoclinic, space
group P21/c, a 9.396(2), b 33.792(5), c 11.276(2) Å, β 115.129(8)Њ,
U 3241(1) Å3, Dc 1.33 g cmϪ3, Z 8, µCu 6.03 cmϪ1. Crystal size
0.11 × 0.11 × 0.40 mm, 2θmax 140Њ, minimum and maximum
transmission factors 0.83 and 0.94. The number of reflections
was 3099 considered observed out of 5673 unique data, with Rint
0.018 for 51 pairs of equivalent 0kl reflections. After refinement
on F, final residuals R, RЈ were 0.055, 0.077 for the observed data.
3280w, 1660s, 1585m, 1530m, 1190m and 840s cmϪ1
.
For [CuL1 ][PF6]2. C42H32CuF12N8P2,
M
1002.2, ortho-
rhombic, space group P212121, a 9.124(1), b 13.753(2), c
33.070(5) Å, U 4149.8(9) Å3, Dc 1.60 g cmϪ3, Z 4, µCu 23.43 cmϪ1
[FeL9 ][BF4]2. The compound Fe(BF4)2ؒ6H2O (53 mg, 0.16
2
2
mmol) in ethanol (15 cm3) was added to L9 (150 mg, 0.32 mmol)
dissolved in ethanol (700 cm3) heated at reflux. After 30 min an
excess of aqueous ammonium tetrafluoroborate was added and
the solution volume reduced to 400 cm3. The solution was
cooled and the resulting solid filtered off and washed with
diethyl ether. The solid was then purified by flash chrom-
atography [silica, acetonitrile–water–saturated KNO3 (aq)
20:2:1 eluent]. The initial purple band was collected and pre-
cipitated by the addition of an excess of aqueous ammonium
tetrafluoroborate (10 cm3) and then recrystallisated from aque-
ous acetonitrile to give a purple microcrystalline solid (95 mg,
50%) (Found: C, 56.51; H, 4.44; N, 8.65. Calc. for C58H44B2Fe-
F8N8O6ؒ3H2O: C, 56.52; H, 4.06; N, 9.09%). ES mass spectrum:
m/z 502 (M2ϩ) and 1091 ([M ϩ BF4]ϩ). 13C NMR [(CD3)2CO]:
δ 183.43, 180.03, 160.24, 160.03, 158.09, 152.97, 148.44, 144.18,
140.73, 138.95, 132.05, 128.98, 127.74, 124.18, 123.42, 120.89,
104.77, 99.54, 65.52 and 13.98. IR (Nujol mull): 3270w, 1658m,
.
Crystal size 0.09 × 0.13 × 0.30 mm, 2θmax 140Њ, minimum and
maximum transmission factors 0.62 and 0.83. The number of
reflections was 3398 considered observed out of 4416 unique
data. After refinement on F, final residuals R, RЈ were 0.052,
0.070 for the observed data.
Structure determinations. Reflection data were measured at
294 K with an Enraf-Nonius CAD-4 diffractometer in θ–2θ
scan mode using nickel-filtered copper radiation (λ 1.5418 Å).
Data were corrected for absorption using the analytical method
of De Meulenaer and Tompa.31 Reflections with I > 3σ(I ) were
considered observed. The structures were determined by direct
phasing and Fourier methods.
For L1 the structure obtained had the two independent mol-
ecules of the asymmetric unit related approximately by a trans-
lation of a/2, and consequently reflection data with h = 2n ϩ 1
were systematically weak. Constrained refinement was used in
order to minimise problems caused by the pseudo-symmetry
and the relatively small number of observed reflections. Each
molecule was modelled as four planar groups, the two outer
1582m, 1525m, 1187m and 1050m (br) cmϪ1
.
[ZnL9 ][PF6]2. The compound Zn(O2CMe)2ؒ2H2O (39 mg,
2
0.18 mmol) in ethanol (10 cm3) was added to L9 (170 mg, 0.36
mmol) in ethanol (700 cm3) heated at reflux. After 30 min an
J. Chem. Soc., Dalton Trans., 1997, Pages 3011–3028
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8 R. P. Thummel, V. Hegde and Y. Jahng, Inorg. Chem., 1989, 28,
pyridyl groups being the same, and with the corresponding
groups in each molecule being identical. Three sets of sub-
sidiary coordinates, all with z = 0, were used to define the differ-
ent types of planar groups present, and each group in the two
molecules was defined by transformation of the appropriate set
of subsidiary coordinates to a local axial system, refineable for
rotation and translation. Appropriate x and y coordinates for
the subsidiary atoms were refined, and planarity was main-
tained by keeping z = 0 in all cases. Corresponding intergroup
distances were slack-constrained to approach equality, but
there were no constraints on rotations between groups in the
molecules. Hydrogen atoms were included in positions calcu-
lated each cycle. Thermal motions were refined using 12-
parameter TL rigid-body models for the groups, with the
centres of libration of the peripheral groups fixed at their points
of attachment to the central ring. The central ring showed no
significant librational motion. Hydrogen atom thermal motions
were included in the appropriate group.
3264; M. Beley, J.-P. Collin, J.-P. Sauvage, H. Sugihara, F. Heisel and
A. Miehé, J. Chem. Soc., Dalton Trans., 1991, 3157; C. R. Hecker,
A. K. I. Gushurst and D. R. McMillin, Inorg. Chem., 1991, 30, 538;
E. Amouyal, M. Mouallem-Bahout and G. Calzaferri, J. Phys.
Chem., 1991, 95, 7641; E. Amouyal and M. Mouallem-Bahout,
J. Chem. Soc., Dalton Trans., 1992, 509; M. Maestri, N. Amaroli,
V. Balzani, E. C. Constable and A. M. W. Cargill Thompson, Inorg.
Chem., 1995, 34, 2759.
9 W. R. McWhinnie and J. D. Miller, Adv. Inorg. Chem. Radiochem.,
1969, 12, 135.
10 E. C. Constable, Prog. Inorg. Chem., 1994, 42, 67; J.-P. Sauvage,
J.-P. Collin, J. C. Chambron, S. Guillerez, C. Coudret, V. Balzani,
F. Barigelletti, L. De Cola and L. Flamigni, Chem. Rev., 1994, 94,
993; E. C. Constable, in Transition Metals in Supramolecular Chem-
istry, eds. L. Fabbrizzi and A. Poggi, Kluwer, Dordrecht, 1994,
p. 81; A. Harriman and J.-P. Sauvage, Chem. Soc. Rev., 1996, 41;
A. Harriman and R. Ziessel, Chem. Commun., 1996, 1707.
11 (a) E. C. Constable, A. M. W. Cargill Thompson, P. Harveson,
L. Macko and M. Zehnder, Chem. Eur. J., 1995, 1, 360; (b) E. C.
Constable and P. Harveson, Chem. Commun., 1996, 33; (c) E. C.
Constable and P. Harveson, Chem. Commun., 1996, 1821; (d) D.
Armspach, M. Cattalini, E. C. Constable, C. E. Housecroft and
D. Phillips, Chem. Commun., 1996, 1823; ( f ) E. C. Constable and
R. A. Fallahpour, J. Chem. Soc., Dalton Trans., 1996, 2389; (e) B.
Whittle, S. R. Batten, J. C. Jeffery, L. H. Rees and M. D. Ward,
J. Chem. Soc., Dalton Trans., 1996, 4249.
For [CuL1 ][PF6]2, hydrogen atoms were included in calcu-
2
lated positions and assigned thermal parameters equal to those
of the atom to which they were bonded. Positional and aniso-
tropic thermal parameters for the non-hydrogen atoms were
refined using full-matrix least squares.
For both structures, reflection weights used were 1/σ2(Fo),
12 E. C. Constable and A. M. W. Cargill Thompson, J. Chem. Soc.,
Dalton Trans., 1992, 3467; 1995, 1615.
¹
2
2
²
with σ(Fo) being derived from σ(Io) = [σ (Io) ϩ (0.04Io) ] . The
2
2
¹
13 M. P. O’Niel, M. P. Niemczyk, W. A. Svec, D. Gosztola, G. L. Gains
III and M. R. Wasielewski, Science, 1992, 257, 63; M. Ohkohchi,
A. Takahashi, N. Mataga, T. Okada, A. Osuka, H. Yamada and
K. Maruyama, J. Am. Chem. Soc., 1993, 115, 12 137; A. Osuka,
S. Nakajima, T. Okada, S. Taniguchi, K. Nozaki, T. Ohno, I. Yama-
zaki, Y. Nishimura and N. Mataga, Angew. Chem., Int. Ed. Engl.,
1996, 35, 92; C. A. Hunter and R. K. Hyde, Angew. Chem., Int.
Ed. Engl., 1996, 35, 1936; M. P. Debreczeny, W. A. Svec and M. R.
Wasielewski, Science, 1996, 274, 584.
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²
weighted residual is defined as RЈ = (Σw∆ /ΣwFo ) . Atomic scat-
tering factors and anomalous dispersion parameters were from
ref. 32. Structure solutions were by MULTAN 8033 and refine-
ments used RAELS for L1 and BLOCKLS, a local version of
ORFLS,34 for [CuL1 ][PF6]2; ORTEP II 20 running on a Mac-
2
intosh IIcx was used for the structural diagrams, and a DEC
Alpha-AXP workstation was used for calculations.
CCDC reference number 186/597.
Acknowledgements
Support from the Australian Research Council is gratefully
acknowledged.
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17 E. Campaigne, W. E. Budd and G. F. Schaefer, Org. Synth., 1963,
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Received 23rd April 1997; Paper 7/02778H
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J. Chem. Soc., Dalton Trans., 1997, Pages 3011–3028