Photochemical and thermal synthesis and characterization of polypyridine ruthenium(II) complexes containing different monodentate ligands

Article abstract of DOI:10.1039/b310198c

The photochemical and thermal synthesis of a series of [Ru(tpy)(phen)L]²⁺ complexes where terpy = 2,2′:6′,2″-terpyridine (terpy) or 4-(3,5-di-tert-butyl)phenyl-2,2′;6′,2″-terpyridine (terpy*), phen = 1,10-phenanthroline and L monodentate ligands such as Cl^-, NC^-, CH₃CN, pyridine, isoquinoline (iq), 4-dimethylaminopyridine (dmap), 4-(4′-methylpyridinium)pyridine (mqt), phenothiazine (ptz), 3,5-lutidine(lut) and H₂O are described. The complexes have been characterized by ¹H (COSY and ROESY) NMR spectroscopy, mass spectrometry (FAB and ES-MS), cyclic voltammetry, UV-vis absorption and emission spectroscopy and single-crystal X-ray diffraction. Photochemical experiments have shown that the ligands L can be photochemically expelled and replaced by CH₃CN molecules used as solvent. This type of ligand interchange occurs efficiently and very selectively. The reaction has the potential to be applied to a wide range of entering ligands (thioethers, ethers, pyridines, sulfoxides, nitriles, amides) and indicates the high stability of the Ru(terpy)(phen) core under the irradiation conditions.

Full text of DOI:10.1039/b310198c

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Photochemical and thermal synthesis and characterization of
polypyridine ruthenium(II) complexes containing different
monodentate ligands†
Sylvestre Bonnet,a Jean-Paul Collin,*a Nathalie Gruber,b Jean-Pierre Sauvagea and
Emma R. Schofield‡a
a Laboratoire de Chimie Organo-Minérale, UMR 7513 du CNRS, Université Louis Pasteur,
Faculté de Chimie, 4, rue Blaise Pascal, 67070 Strasbourg Cedex, France
b Service Commun des rayons X, Université Louis Pasteur, Faculté de Chimie, 4,
rue Blaise Pascal, 67070 Strasbourg Cedex, France. E-mail: jpcollin@chimie.u-strasbg.fr
Received 26th August 2003, Accepted 23rd October 2003
First published as an Advance Article on the web 10th November 2003
The photochemical and thermal synthesis of a series of [Ru(tpy)(phen)L]2ϩ complexes where terpy = 2,2Ј:6Ј,2Љ–
terpyridine (terpy) or 4-(3,5-di-tert-butyl)phenyl-2,2Ј;6Ј,2Љ-terpyridine (terpy*), phen = 1,10-phenanthroline and L
monodentate ligands such as ClϪ, NCϪ, CH3CN, pyridine, isoquinoline (iq), 4-dimethylaminopyridine (dmap),
4-(4Ј-methylpyridinium)pyridine (mqt), phenothiazine (ptz), 3,5-lutidine(lut) and H2O are described. The complexes
have been characterized by 1H (COSY and ROESY) NMR spectroscopy, mass spectrometry (FAB and ES-MS),
cyclic voltammetry, UV-vis absorption and emission spectroscopy and single-crystal X-ray diffraction.
Photochemical experiments have shown that the ligands L can be photochemically expelled and replaced by CH3CN
molecules used as solvent. This type of ligand interchange occurs efficiently and very selectively. The reaction has the
potential to be applied to a wide range of entering ligands (thioethers, ethers, pyridines, sulfoxides, nitriles, amides)
and indicates the high stability of the Ru(terpy)(phen) core under the irradiation conditions.
is probably the result of the conjunction of unfavourable
Introduction
parameters such as low quantum yields and poor selectivity.
Current interest in the chemistry and particularly in the photo-
A few representative examples11 involve the Ru(bidentate)2
chemistry of ruthenium() complexes arises from their poten-
core, one of the most frequently used chemical subunits in
ruthenium() chemistry. In this work, photochemical and
thermal reactions have both been employed to prepare
tial use in solar energy conversion processes,1 or as components
of luminescent sensors,2 light emitting diodes3 and more gener-
ally photoswitchable molecular devices.4 In this latter field,
ruthenium complexes in good yields. The classical thermal
reversible light-driven reactions such as photoisomerisation5 or
route described in the literature12 allows the preparation of the
photosubstitution6 occurs and could permit the control of
intermediate compounds Ru(terpyridine)Cl3, [Ru(terpyrid-
large amplitude motion in specially designed systems.7 In
ine)(phen)Cl]ϩ and [Ru(terpyridine)(phen)(CH3CN)]2ϩ as well
our efforts to develop molecular machines which operate under
light irradiation, we recently described different ruthenium
as the complex 10 (terpyridine = terpy or terpy*). Chart 1 gives
the chemical formulae of the compounds synthesized.
systems based on the expulsion of bipyridine or pyridine
By reaction with AgBF4, the precursor of the type [Ru(terpy)-
ligands.8 As already demonstrated in several ruthenium com-
plexes, the excitation of the MLCT band allows the thermal
(phen)Cl]ϩ leads to compounds 2 and 9, conducting the reac-
tion in acetonitrile–H2O or acetone–H2O mixture, respectively.
Surprisingly, these reaction conditions afforded also, in the
population of low-lying d–d states from the MLCT excited
state and subsequent expulsion of the weaker ligand.9 In the
case of 2, a by-product which was identified as [Ru(terpy)-
[Ru(terpy)(6,6Ј-dmbp)L]2ϩ type complex (terpy = 2,2Ј:6Ј,2Љ-
(phen)(CN)]ϩ by determining its X-ray structure. The condi-
terpyridine, 6,6Ј-dmbp = 6,6Ј-dimethyl-2,2Ј-bipyridine) where L
tions of formation of this compound remain unclear at the
moment. In order to avoid this side reaction some photo-
is acetonitrile or pyridine,8b a reversible interchange of ligand
occurs efficiently and quantitatively. In this paper we will extend
the previous study to a series of L ligands including iso-
quinoline (iq), 4-dimethylaminopyridine (dmap), 4-(4Ј-methyl-
pyridinium)pyridine (mqt), phenothiazine (ptz), 3,5-lutidine
(lut) and H2O in complexes containing 1,10-phenanthroline
and two types of terpyridine: terpy and 4-(3,5-di-tert-butyl)-
phenyl-2,2Ј;6Ј,2Љ-terpyridine (terpy*).
chemical attempts were made starting from [Ru(terpy)-
(phen)Cl]ϩ. Irradiation of 1 in CH3CN–H2O mixture with
white light from a slide projector led to 2 without an isolable
amount of 3. This method turned out to be very efficient and
compounds 4–8 have been prepared using 10 equivalents excess
of the ligand L in deoxygenated acetone. The only exception
was the synthesis of 4 which was carried out in neat pyridine.
Crystal structures
Results and discussion
The structures of each of the ten cationic complexes have been
determined by X-ray crystallography at 173 K. The ORTEP
Synthesis
diagrams of compounds 1–10 are shown in Fig. 1.
Selected bond lengths and bond angles are given in Tables
1–4.
Photochemical methods for preparing polypyridine ruthenium
complexes are relatively scarce in the literature.10 This situation
A number of structures have been published with the general
formula [Ru(terpy)(N–N)L]nϩ where N–N is bipyridine,9a,13 bi-
quinoline,14 or bipyrazine15 and L is a monodentate ligand.
Only one structure involves a phenanthroline derivative16 as
bidentate ligand and this is the first time that a systematic series
† Electronic supplementary information (ESI) available: View of the
dimeric units of 8 and proton indexation used in the 1H NMR data. See
http://www.rsc.org/suppdata/dt/b3/b310198c/
‡ Present address: Department of Chemistry, Trinity College, College
Green, Dublin 2, Ireland.
D a l t o n T r a n s . , 2 0 0 3 , 4 6 5 4 – 4 6 6 2
T h i s j o u r n a l i s © T h e R o y a l S o c i e t y o f C h e m i s t r y 2 0 0 3
4654

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Chart 1
Table 1 Bond lengths (Å) from the ruthenium ion to the coordinating
atoms for the complexes 1 to 5
Table 2 Bond lengths (Å) from the ruthenium ion to the coordinating
atoms for the complexes 6–10
1
2
3
4
5
6
7
8
9
10
Ru–N1
Ru–N2
Ru–N3
Ru–N4
Ru–N5
Ru–La
2.105(2)
2.051(3)
2.074(3)
1.961(2)
2.084(3)
2.4180(8)
2.093(4)
2.054(4)
2.081(4)
1.973(4)
2.075(4)
2.041(5)
2.104(2)
2.121(2)
2.076(2)
1.973(2)
2.090(2)
2.004(3)
2.112(4)
2.074(4)
2.088(4)
1.981(4)
2.078(4)
2.113(4)
2.107(4)
2.060(4)
2.057(4)
1.953(4)
2.082(4)
2.091(4)
Ru–N1
Ru–N2
Ru–N3
Ru–N4
Ru–N5
Ru–La
2.111(2)
2.062(2)
2.079(2)
1.967(2)
2.079(3)
2.107(2)
2.104(8)
2.069(8)
2.068(9)
1.956(8)
2.056(9)
2.375(3)
2.101(9)
2.049(8)
2.072(8)
1.951(9)
2.072(9)
2.100(8)
2.072(6)
2.024(6)
2.066(7)
1.966(6)
2.077(6)
2.142(5)
2.106(4)
2.056(4)
2.070(4)
1.963(4)
2.068(4)
2.118(4)
a L = Cl for 1; L = C28 for 3 and L = N6 for 2, 4 and 5.
a L = S for 7; L = O1 for 9 and L = N6 for 6,8 and 10.
of structures has been investigated. In all the structures of the
present series, the Ru() ions are in pseudo-octahedral
environments with noticeable asymmetric bond distances to the
different coordinated atoms. Characteristic of the Ru()–terpy-
ridine complexes, the Ru()–nitrogen bond to the central
pyridine is shorter than those to the outer two pyridines by 0.1–
0.12 Å, as a result of the steric constraint imposed by the tri-
dentate ligand. For a similar reason, the bite angle between the
metal and the two outer pyridine rings of the terpy is 158.6–
159.3Њ, i.e. significantly smaller than the 180Њ required for ideal
octahedral geometry. Only minor variations in the Ru–N(terpy)
bond lengths are observed throughout the series, none of which
suggest any significant perturbation by ligand L.
length is 2.067 Å.17 However, looking at this structure in more
detail it is apparent that one of the three phen ligands has one
short and one long bond to the Ru(), 2.058 and 2.082 Å,
respectively. This is as a result of steric congestion around the
metal centre. In the series of structures presented here the two
Ru()–N(phen) bond lengths are also noticeably different:
between the elongated Ru–N bond lengths (2.093–2.112 Å) and
the standard axial bond lengths (2.049–2.074 Å) a difference of
0.038–0.052 Å is observed in all complexes except 3. The obser-
vation of one shorter and one longer Ru()–N(phen) bond in
complexes such as these was originally made for [Ru(terpy)-
(bpy)(py)]2ϩ, in which the difference between the Ru–N bond
lengths in the bpy ligand is about 0.04 Å. In this complex, as
well as in the novel series discussed here, the longer bond is the
one trans to the central pyridine of the terpy ligand.9a This is
A more significant variation is observed in the Ru–N(phen)
bond lengths. In [Ru(phen)3]2ϩ the average Ru–N(phen) bond
D a l t o n T r a n s . , 2 0 0 3 , 4 6 5 4 – 4 6 6 2
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Fig. 1 View of the crystal structures of the ruthenium complexes 1–10. Solvent molecules, H atoms and anions are omitted for clarity. Ellipsoids are
scaled to enclose 50% of the electronic density.
also true for the literature structures listed above. In the case of
3, the equatorial Ru()–N(phen) bond is 2.104(2) Å which is
again elongated in comparison to Ru(phen)32ϩ. However, the
axial Ru()–N(phen) bond is even longer (2.121(2) Å), an
observation which cannot be explained by steric crowding,
particularly since the same phenomenon is not present in 2
which has the same steric requirements. In 3, a significant
degree of back-bonding to the metal would explain the
short Ru()–CN bond, the long Ru()–N(phen) bond trans to
the CN and the lack of the same effect in 2. The Ru()–L bond
lengths can be compared to those from literature structures
containing a different bidentate ligand than phen. In 1, the
Ru–Cl bond length of 2.418(8) Å is similar to that found in
analogous complexes such as [Ru(terpy)(bpz)Cl]ϩ (2.4050(5)
D a l t o n T r a n s . , 2 0 0 3 , 4 6 5 4 – 4 6 6 2
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Table 3 Bond angles (Њ) between the ruthenium ion and the coordinating atoms for the complexes 1–5
1a 3b
2
4
5
N1–Ru–N2
N1–Ru–N3
N1–Ru–N4
N1–Ru–N5
N1–Ru–N6
N2–Ru–N3
N2–Ru–N4
N2–Ru–N5
N2–Ru–N6
N3–Ru–N4
N3–Ru–N5
N3–Ru–N6
N4–Ru–N5
N4–Ru–N6
N5–Ru–N6
79.38(9)
79.6(2)
78.66(9)
79.4(1)
79.4(2)
98.0(2)
99.9(1)
173.90(9)
101.17(9)
93.51(7)
90.8(1)
94.5(1)
92.3(1)
172.82(7)
79.5(1)
158.9(1)
89.41(7)
79.5(1)
92.56(7)
90.01(7)
101.1(2)
174.8(2)
99.8(2)
95.8(2)
88.6(2)
95.2(2)
93.3(2)
175.3(2)
79.2(2)
159.0(2)
91.1(2)
79.7(2)
89.3(2)
88.7(2)
100.31(9)
171.73(9)
100.97(9)
91.9(1)
90.67(8)
93.08(9)
91.87(8)
170.6(1)
79.35(9)
158.7(1)
91.7(1)
104.5(1)
172.2(1)
96.7(1)
95.0(1)
85.8(1)
94.3(1)
95.6(1)
170.9(1)
79.4(2)
158.6(1)
88.7(1)
79.2(1)
91.8(1)
92.2(1)
173.5(2)
102.1(2)
95.8(2)
88.3(2)
94.4(2)
89.9(2)
175.0(2)
79.7(2)
159.1(2)
93.9(2)
79.7(2)
90.4(2)
89.7(2)
79.35(9)
96.3(1)
89.3(1)
a N6 = Cl. b N6 = C28.
Table 4 Bond angles (Њ) between the ruthenium ion and the coordinating atoms for the complexes 6–10
7a 9b
6
8
10
N1–Ru–N2
N1–Ru–N3
N1–Ru–N4
N1–Ru–N5
N1–Ru–N6
N2–Ru–N3
N2–Ru–N4
N2–Ru–N5
N2–Ru–N6
N3–Ru–N4
N3–Ru–N5
N3–Ru–N6
N4–Ru–N5
N4–Ru–N6
N5–Ru–N6
79.35(9)
79.5(4)
79.5(4)
96.3(4)
80.4(2)
79.4(2)
104.3(2)
173.7(2)
96.4(2)
96.2(2)
88.8(2)
95.7(2)
92.1(2)
173.4(2)
79.3(2)
159.1(2)
87.6(2)
79.8(2)
89.1(2)
93.3(2)
102.60(9)
174.7(1)
98.42(9)
94.95(9)
90.78(9)
95.78(9)
90.14(9)
173.73(9)
79.51(9)
158.8(1)
87.88(9)
79.3(1)
96.5(3)
172.1(4)
103.9(3)
93.4(3)
91.6(4)
93.3(4)
88.3(3)
172.8(3)
80.1(4)
159.2(3)
90.6(3)
79.2(4)
93.8(3)
92.2(2)
102.0(3)
177.2(3)
98.3(3)
90.9(2)
88.5(2)
97.3(2)
89.5(2)
171.3(2)
79.5(2)
159.0(2)
92.8(2)
80.0(2)
91.4(2)
92.4(2)
172.0(3)
104.0(4)
95.9(3)
94.0(3)
93.5(4)
85.9(3)
172.9(3)
80.2(4)
159.3(4)
91.8(3)
79.2(4)
91.5(3)
90.1(3)
90.00(9)
93.33(9)
a N6 = S. b N6 = O1.
Å),15 [Ru(tterpy)(mapH)Cl]ϩ (2.3917(8) Å)16 and [Ru(terpy)-
(biq)Cl]ϩ (2.378(2) Å)14 (tterpy = 4Ј-tolyl-2,2Ј:6Ј,2Љ–terpyridine
and mapH = 2-anisyl-1,10-phenanthroline). The Ru–NCCH3
bond (2.041(5) Å) is slightly longer than that in [Ru(terpy)-
(bpy)(CH3CN)]2ϩ (2.030(10) Å),13a while the remaining pyrid-
ine-based structures have Ru–L bond lengths in the range of
2.091–2.113 Å which corresponds well to that of [Ru(terpy)-
(bpy)(pz)]2ϩ (2.091(9) Å) and [Ru(terpy)(bpy)(py)]2ϩ (2.114(6)
Å), (pz = pyrazine). In 7, the side-on coordination type of the
PTZ ligand is comparable to that observed in cis- or trans-
it seems reasonable to conclude that there is only limited
electronic delocalisation within this ligand, although in solution
it will undergo free rotation. As already observed before in simi-
lar compounds,13a another consequence of the packing effect is
a distortion in the planarity of the terpyridine ligand occuring
in complexes 5 and 9. This is probably due to the overlap
between the terpyridine rings of neighbouring molecules in the
lattice.
Electrochemistry
18
[Ru(bpy)2(ptz)2][PF6]2 and [Ru(NH3)4(mqt)(ptz)][PF6]3.19 The
Ru–S bond length of 2.375(3) Å and the average of the N–Ru–S
bond angles in 7 are also similar to these complexes. In 9, the
Ru–O(H2O) distance, 2.142(5) Å is found to be almost identi-
cal to that in the complex [Ru(terpy)(2-phenylazopyridine)-
(H2O)]2ϩ (2.140(5) Å)20 but slightly longer than in other related
complexes.21
Although there is no close analogue of [Ru(terpy)(bpy)-
(mqt)]2ϩ already published, the value of 2.097(3) Å for the
Ru–N(mqt) bond length of trans-[Ru(NH3)4(ptz)(mqt)]3ϩ 19 is
close enough to that of 8 (2.100(8) Å) to suggest that the com-
plex is not distorded. Interestingly, complex 8 forms dimeric
units which are arranged in interlocked sheets separated by
counterions and solvent molecules (see ESI†). The major differ-
ence between the two units in the dimer is the degree to which
the mqt is twisted out of the plane of the phen, 47 and 62Њ, and
the extent of twisting between the two pyridyl rings of the mqt
unit which is 42 and 30Њ. Given the large degree of twisting
within the ligand and the intra-ring bond length of 1.47 Å,
which is significantly longer than the inter-ring bonds (1.35 Å),
Table 5 summarizes the electrochemical data obtained in
CH3CN for the series of complexes 1–12. Since complex 9
undergoes an immediate solvolysis in CH3CN, its electro-
chemical behaviour was examined in an acetone–water mixture
(95/5, v/v). All the complexes studied display a reversible metal-
centered process and two reversible ligand-centered processes
corresponding to the formation of radical anions, as electrons
are added to the π* orbitals of the ligands. By comparison with
ligand reduction processes occuring in [Ru(phen)3]2ϩ (Ϫ1.41 V),
[Ru(terpy)2]2ϩ (Ϫ1.29 and Ϫ1.54 V) and ESR measurements
performed on [Ru(terpy)(bpy)(py)]2ϩ 22
, it can be assumed that
the first one-electron reduction concerns the terpyridine and the
second concerns the phenanthroline. The redox potential of
the Ru(/) couple is highly dependent on the σ-donor and
π-acceptor properties of the coordinated ligands. In this series,
terpy and phen are the better π-acceptor ligands, so the redox
potential of the metal is mainly influenced by the σ-donating
ability of the sixth monodentate ligand.23 From Table 5 it
is clear that good σ-donor ligands such as ClϪ in 1 and
D a l t o n T r a n s . , 2 0 0 3 , 4 6 5 4 – 4 6 6 2
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Table 5 Cyclic voltammetry data of the complexes 1–12 in CH3CN, except 9 which is in acetone–water (95/5, v/v); (Bun NPF6 0.1 M, v = 100 mV
4
sϪ1
)
E1/2/V vs. SCE (|Epa Ϫ Epc|/mV)
Complex
Ru(/)
0.78 (70)
1.27 (60)
1.05 (60)
1.23 (70)
1.23 (70)
1.05 (60)
mqtϩ/0
terpy/terpyϪ
Ϫ1.44 (80)
Ϫ1.31 (60)
Ϫ1.40 (60)
Ϫ1.26 (60)
Ϫ1.26 (60)
Ϫ1.30 (70)
Ϫ1.32 (90)
Ϫ1.26 (60)
Ϫ1.24 (70)
Ϫ1.27 (60)
Ϫ1.44 (70)
Ϫ1.28 (70)
mqt0/Ϫ1
phen/phenϪ
Ϫ1.59 (80)
Ϫ1.60 (60)
Ϫ1.70 (70)
Ϫ1.59 (70)
Ϫ1.59 (70)
Ϫ1.62 (80)
Ϫ1.60 (60)
Ϫ1.59 (70)
Ϫ1.42 (100)
Ϫ1.59 (60)
Ϫ1.59 (80)
Ϫ1.58 (80)
1
2
3
4
5
6
7b
8
1.28 (60); 1.05 (150)
1.26 (80)
Ϫ0.77 (60)
Ϫ1.44 (70)
9
0.89 (100)a
1.20 (60)
10
11
12
0.79 (60)
1.27 (60)
a Two-electron redox process. b Additional reduction peak at 0.66 V.
Table 6 Electronic spectral data of the complexes 1–12 in CH3CN,
except 9 which is in CH2Cl2
dimethylaminopyridine in 6 shift the redox potential of the
metal to much less positive values than those observed for 4.
Isoquinoline and 3,5-dimethylpyridine have σ-donor proper-
ties similar to pyridine, and therefore have little effect on the
Ru(/) process, while this process in 8, in which the ligand is
positively charged, occurs at a slightly more positive potential.
For this complex, four reversible reduction waves are observed,
at Ϫ0.77, Ϫ1.26, Ϫ1.44, Ϫ1.59 V. The first corresponds to the
reduction of the monocationic mqtϩ ligand giving [Ru(terpy)-
Emission
a
Complex
Absorption λmax/nm (10Ϫ3ε/MϪ1cmϪ1
)
λmax/nmb
1
2
380 (3.05), 439 (6.04), 502 (9.43)
398sh (7.37), 455 (11.51)
357 (3.36), 417sh (6.87), 486 (11.73)
411 (7.74), 467 (9.26)
370 (7.55), 416 (11.79), 472 (9.90)
364 (5.42), 416 (7.82), 474 (8.51)
413 (6.93), 461sh (6.14)
710
–
630
640
640
670
–
3
4
(phen)(mqtϩ )]2ϩ. The reduction of this species, which occurs
ؒ
5
6
ϩ
ϩ
on the terpy ligand giving [Ru(terpyϪ )(phen)(mqt )] , is fol-
ؒ
ؒ
7
lowed by a second process based on the neutral mqt ligand,
8
441 (10.90), 475sh (8.84)
314 (35.5), 486 (13.7)
–
–
Ϫ
which gives [Ru(terpyϪ )(phen)(mqt )], and the final process
ؒ
ؒ
9
occurs on the phen ligand giving [Ru(terpyϪ )(phen )(mqt )]–.
The two additional waves can be assigned to the reduction of
the alkylated pyridine unit since the free N-methyl-4,4Ј-bi-
pyridinium salt undergoes reduction processes at Ϫ0.92 and
Ϫ1.62 V,24 which are shifted to more positive potentials by
approximately 200 mV on coordination to Ru().19 The electro-
chemical behavior of 7 is more complicated since two reversible
anodic processes are observed at 1.05 and 1.28 V along with a
third process at 0.66 V, which is present only in the return wave.
The process at 1.05 V is thought to be that of 7, which under-
goes ligand dissociation on oxidation to give 2, the Ru(/)
process of which occurs at 1.28 V. The process at 0.66 V is
ascribed to the reduction of the dissociated ptz radical cation:
this process is present even when the potential of the CV is
switched at 1.2 V, demonstrating it is not a product of the pro-
cess at 1.28 V. This electrochemically induced ligand dissoci-
ation is not observed for any of the other complexes in the
series, but has been documented in the analogous complex
Ϫ
Ϫ
ؒ
ؒ
ؒ
10
11
12
395sh (6.8), 468sh (10.6), 487 (11.4)
316 (25.5), 510 (11.7)
310 (39.9), 464 (17.8)
640
727
614
a 293 K. b Deoxygenated solvent, λex = λmax of the MLCT band, 293 K.
[Ru(terpy)(bpy)(ptz)]2ϩ 18
. Complex 9 shows a single redox wave
at surprisingly high potential (0.89 V) corresponding to a two-
electron redox process. As indicated by its broad shape (∆Ep =
100 mV) this wave is probably due to two very close one-elec-
tron processes Ru(/) and Ru(/) associated with proton-
coupled reactions such as that of [Ru(tpy)(bpz)(H2O)]2ϩ which
is thought to undergo a two-proton, two-electron oxidative
Fig. 2 Visible electronic spectra of 1, 4, 6, 7 and 8 in CH3CN.
charge transfer bands (1MLCT) are observed in the visible
region (Table 6 and Fig. 2).
Since the energy of the π* orbitals of the terpy and phen
acceptor ligands is not affected by minor changes in the ligand
field around the metal, the wavelength of the MLCT bands is
determined by the energy of the metal d(t2g) orbitals, which is
modified by the donor or acceptor nature of ligand L. As the
σ-donor ability of the ligand increases, the absorption maxi-
mum wavelength (nm) of the complexes with the terpy ligand
shifts to lower energy following the series: 8 (441) < 4 (467) <
5 (472) < 6 (474) < 1 (502). In the case of 5 the most intense
absorption occurs at 416 nm; however, this can be assigned to
the Ru–isoquinoline absorption since it occurs in the same
position as the Ru–pyridine transition (413 nm) but with
greater intensity due to increased conjugation. A ligand such as
CH3CN, which is a strong π-acceptor and weak σ-donor, lowers
the energy of the metal d(t2g) orbitals compared to pyridine,
process to give [Ru(tpy)(bpz)(O)]2ϩ 15 Such behaviour has also
.
been observed in other ruthenium polypyridine aqua com-
plexes15,20,25 in which the Ru() oxidation state is unstable with
respect to disproportionation in the considered medium.This
observation is in accordance with the electrochemical behavior
of [Ru(terpy)(phen)(H2O)]2ϩ, which posesses the smallest ∆E1/2
value (∆E1/2 = EЊ(RuIV/III) Ϫ EЊ(RuIII/II)) of the 22 complexes of
this type.26
Spectroscopic properties
The absorption spectra for all the complexes are dominated by
intense ligand centered (π–π*) transition bands in the ultra-
violet region while unresolved overlapping metal-to-ligand
D a l t o n T r a n s . , 2 0 0 3 , 4 6 5 4 – 4 6 6 2
4658

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Table 7 Crystallographic data for 1–5
1
2
3
4
5
Formula
Mr
C31H25ClF6N7PRu
777.08
C33H28F12N8P2Ru
927.64
C28H21F6N6OPRu
703.55
C38H30F12N6P2Ru
961.70
C79H60Cl2F24N12P4Ru2
2030.34
Crystal system
Space group
a/Å
b/Å
c/Å
α/Њ
β/Њ
Triclinic
P1
Monoclinic
P21/c
8.7526(3)
11.5332(2)
36.851(1)
Triclinic
P1
Monoclinic
P21/c
15.3374(5)
19.8829(8)
12.9446(4)
Monoclinic
C2/c
14.0923(4)
21.9960(8)
25.6543(6)
¯
¯
8.8775(4)
12.0354(5)
15.3203(6)
80.973(8)
80.067(8)
85.708(8)
1590.5(1)
2
8.6848(3)
10.3229(7)
16.632(1)
79.267(5)
77.266(5)
68.952(5)
1347.9(1)
2
92.216(5)
105.241(5)
99.395(5)
γ/Њ
V/Å3
Z
3717.1(3)
4
3808.6(5)
4
7845.5(4)
4
Color
Dc/g cmϪ3
µ/mmϪ1
T/K
Red
1.62
0.697
173
0.038
0.051
Orange
1.66
0.606
173
0.041
0.050
Orange
1.73
0.719
173
0.032
Red
1.68
0.594
173
0.043
0.061
Red
1.72
0.647
173
0.052
0.072
Ra
b
Rw
0.038
a R = Σ||Fo| Ϫ |Fc||/|Fo|. b Rw = [Σw(|Fo| Ϫ |Fc|)2/Σw(|Fo|2)]1/2
.
causing a shift in the MLCT maximum to shorter wavelength
(455 nm). In the case of CNϪ, which is a strong π-acceptor but
also a stronger σ-donor, a bathochromic shift is also observed
(486 nm). According to literature data the complexes of the
type Ru(terpy)(bpy)L2ϩ are generally weak emitters.9a,13a As
indicated in Table 6, emission data shows that some of the
complexes are weakly emissive at room temperature in CH3CN,
that the emission is stronger when L is dimethylaminopyridine,
but that luminescence is quenched in 7, 8 and 9, which suggests
the few examples of photoexchange being used preparatively
to give high yields of the desired compounds. Their success
opens up new routes to efficient synthesis of such complexes
and the high yields of these processes suggest their use in
systems capable of molecular motion.
Experimental
Single crystal X-ray diffraction experiments were carried out
using Kappa CCD and graphite-monochromated Mo-Kα radi-
ation (λ = 0.71073 Å). For all computations, the MolEN pack-
age was used27a and structures were drawn using ORTEP.27b
Crystal data and details of data collection for complexes 1–10
are provided in Tables 7 and 8.
3
3
that the energy difference between the MC and the MLCT
states is small enough for thermal deactivation to proceed by
this pathway.
Photochemical reactivity
CCDC reference numbers 218272–218280 and 218935.
See http://www.rsc.org/suppdata/dt/b3/b310198c/ for crystal-
lographic data in CIF or other electronic format.
The photochemistry of these new ruthenium complexes was
examined both for synthetic utility and as model reactions in
the design of molecular machines triggered by a photonic
signal. The irradiation of 1 for 5 h in CH3CN–H2O affords 2 in
87% yield. Synthesis of complexes 4–8 was carried out by dis-
solving 2 in deoxygenated acetone to which ten equivalents
excess of the ligand L was added. The reaction mixture was
irradiated and the solution stirred under argon while the pro-
gress of the reaction was monitored by thin layer chomato-
graphy. After purification by column chromatography, the
products were isolated as their hexafluorophosphate salts in 78–
82% yields. On irradiation of 4, 6, 7 and 10 in acetonitrile,
photoinduced exchange of ligand L for CH3CN occurs. The
rates of completion of this exchange process vary dramatically
depending on ligand L. When L is phenothiazine the process is
finished after 5 min, while when L is dimethylaminopyridine the
exchange has not reached completion after 16 h. Photolabilis-
ation occurs when the excited complex undergoes a thermally
assisted transition from the MLCT to the MC excited state;
this is also the pathway which leads to luminescence quenching
in the complex. Hence, the complex which luminesces with the
greatest intensity, 6, is the complex for which the photolabilis-
ation process is the slowest. This type of ligand interchange also
occurs efficiently and very selectively with other types of
ligands such as thioethers, ethers, pyridines, sulfoxides, nitriles
and amides.
1H NMR spectra were acquired on either a Bruker WP200
SY (200 MHz) or a Bruker AM 400 (400 MHz) spectrometer,
using the deuterated solvent as the lock and residual solvent as
the internal reference. Mass spectra were obtained by using
a VG ZAB-HF (FAB) spectrometer or a VG-BIOQ triple
quadrupole, positive mode (ES-MS). Photoirradiation was
performed in a quartz UV cell (l = 1.0 cm) or in a NMR tube
(ꢀ = 5.0 mm) using a Hanimex slide projector (250 W halogen
lamp, λ > 400 nm). Electrochemical experiments were per-
formed using an EG&G PAR model 273A potentiostat with a
standard three-electrode configuration. Cyclic voltammetry
was carried out in MeCN solution, using Bu4NPF6 as support-
ing electrolyte, a Pt working electrode, a Pt counter-electrode,
and SCE as reference. The typical sweep rate was 100 mV sϪ1
,
and the window used was from Ϫ2.0 to ϩ1.7 V. Absorption
spectra were recorded with a Kontron Uvikon 860. Emission
spectra were obtained with a SLM Aminco-Bauman Series 2
spectrofluorimeter.
3
3
Chemicals: The ligand terpy* was prepared following liter-
ature procedures.28
Ru(terpy*)Cl3: 4-(3,5-di-tert-butyl)phenyl-2,2Ј;6Ј,2Љ-terpyrid-
ine (201 mg, 0.479 mmol) and one equivalent of RuCl3ؒ3H2O
(125 mg, 0.478 mmol) were dissolved in ethanol (30 cm3). The
solution was heated to reflux for 1 h, cooled and the precipitate
isolated by filtration. The orange solid was washed twice with
ethanol, once with water, once with diethyl ether and air dried
(Yield 299 mg, 99.5%). FAB-MS m/z (calc.): 628.1 (628.1,
[M]ϩ), 593.1 (593.1, [M Ϫ Cl]ϩ), 558.1 (558.1, [M Ϫ 2 Cl]ϩ),
523.2 (523.2, [M Ϫ 3 Cl]ϩ).
Conclusion
A series of ruthenium complexes of formula [Ru(terpy)-
(phen)(L)]nϩ has been prepared and fully characterized. The
electrochemical and photophysical properties of the metal
complex can be altered depending on the nature of the ligand
L. The synthetic procedures detailed in this study are among
1: [Ru(terpy)(phen)Cl][PF6]. A mixture of Ru(terpy)Cl3
(500 mg, 1.13 mmol), 1,10-phenanthroline (215 mg, 1.19
D a l t o n T r a n s . , 2 0 0 3 , 4 6 5 4 – 4 6 6 2
4659

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Table 8 Crystallographic data for 6–10
6
7
8
9
10
Formula
Mr
Crystal system
Space group
a/Å
b/Å
c/Å
α/Њ
β/Њ
C38H35F12N9P2Ru
1008.76
C88H74F24N12O2P4Ru2S2
2177.78
C164H140F72N34OP12Ru4
4747.02
C97H112F24N10O7P4Ru2
C55H64F12N6O2P2Ru
1232.16
Monoclinic
C2/c
23.7601(2)
13.1662(1)
37.2176(4)
2312.03
Hexagonal
P3221
13.5432(1)
13.5432(1)
50.1170(3)
90
90
120
7960.8(1)
3
Triclinic
Triclinic
Triclinic
¯
¯
¯
P1
P1
P1
9.0753(2)
11.5163(4)
20.6798(6)
76.071(5)
88.935(5)
89.917(5)
2097.4(1)
2
10.2143(3)
12.4444(5)
19.6448(8)
97.540(5)
94.916(5)
111.387(5)
2280.8(1)
1
17.0076(5)
17.7093(6)
18.7337(5)
62.319(5)
85.332(5)
71.423(5)
4721.4(2)
1
97.638(5)
γ/Њ
V/Å3
Z
11539.5(2)
8
Color
Dc/g cmϪ3
µ/mmϪ1
T/K
Red
1.60
0.545
173
0.038
0.049
Orange
1.59
0.551
173
0.076
Red
1.67
0.548
173
0.084
0.104
Red
1.45
0.443
173
0.073
0.091
Red
1.42
0.411
173
0.066
0.079
Ra
b
Rw
0.092
a R = Σ||Fo| Ϫ |Fc||/|Fo|. b Rw = [Σw(|Fo| Ϫ |Fc|)2/Σw(|Fo|2)]1/2
.
mmol), lithium chloride (265 mg, 6.24 mmol) and triethylamine
(1 cm3) was heated to reflux in EtOH–H2O (3 : 1, 50 cm3) for
4 h. Half of the solvent was removed in vacuo, and the brown
solution was poured into a solution of aqueous KPF6 (100
cm3). The precipitate was collected by filtration, the solvent
removed and the residue separated by column chromatography
(silica: MeCN–H2O–sat.KNO3(aq), 44 : 2 : 1). The major frac-
tion was collected, reduced in volume, and precipitated by the
addition of a solution of aqueous KPF6. The precipitate was
collected by filtration over Celite, redissolved in MeCN and the
solvent removed in vacuo, giving a brown powder (323 mg,
41%). 1H NMR (300 MHz, CD3CN): δ 10.43 (H, dd, J 5.2, 1.2
Hz, HP2), 8.81 (H, dd, J 8.1 Hz, HP4), 8.53 (2H, d, J 8.1 Hz,
HB3), 8.38 (2H, ddd, J 8.1 Hz, HA3), 8.31 (H, dd, HP3), 8.30 (H,
AB, J 8.9 Hz, HP5), 8.22 (H, dd, J 8.1, 1.2 Hz, HP9), 8.13 (H, t,
HB4), 8.02 (H, AB, HP6), 7.83 (2H, ddd, J 1.7 Hz, HA4), 7.65 (H,
dd, J 5.4 Hz, HP7), 7.51 (2H, dm, HA6), 7.28 (H, dd, HP8), 7.12
(2H, ddd, J 7.6, 5.4, 1.2, HA5). Crystals of (1)(PF6)ؒ2CH3CN
were obtained by vapour diffusion, in the dark, of diisopropyl
ether into a solution of the product in CH3CN.
H2O (10 cm3) was irradiated with white light from a slide pro-
jector for 5 h. The solvent was then removed under vacuum
followed by addition of water (10 cm3) and then a solution of
aqueous KPF6 (10 cm3) were added resulting in the precipit-
ation of an orange solid, which was collected by filtration on
Celite. This solid was purified by column chromatography
(silica: MeCN–H2O–sat. KNO3(aq), 44 : 2 : 1). The major,
orange fraction was collected, and the complex was precipitated
by the addition of a solution of aqueous KPF6. Following
filtration, the product was dried in vacuo and isolated as an
orange powder (53 mg, 87%).
3: [Ru(terpy)(phen)(CN)][PF6]. A second product with a
higher Rf value was also isolated in the chromatographic separ-
ation from 2 prepared thermally. The yellow solid was identified
as [Ru(terpy)(phen)(CN)][PF6]. 1H NMR (400 MHz, CD3CN):
δ 10.34 (H, d 4.4 Hz, HP2), 8.78 (H, d, J 8.4 Hz, HP4), 8.52 (2H,
d, J 7.9 Hz, HB3), 8.37 (3H, dm, HA3,P9), 8.28 (H, AB, J 8.8,
HP5), 8.22 (H, dm, HP3), 8.21 (H, t, HB4), 8.11 (H, AB, HP6), 7.88
(2H, ddd, J 7.6 Hz, HA4), 7.63 (H, dd, J 5.2, 1.5 Hz, HP7), 7.55
(2H, dm, J 5.4, HA6), 7.43 (H, dd, J 8.4, 5.2, HP8), 7.14 (2H, ddd,
J 1.5 Hz, HA5). FAB-MS: m/z (calc.) 541.0 (540.6, [M Ϫ 2PF6]),
514.0 (514.6, [Ru(terpy)(phen)]ϩ). Crystals of (3)(PF6)ؒH2O
were obtained by vapour diffusion, in the dark, of diisopropyl
ether into a solution of the product in CH3CN
4: [Ru(terpy)(phen)(py)][PF6]2. A solution of [Ru(terpy)-
(phen)(CH3CN)][PF6]2 (20 mg, 0.024 mmol) in degassed pyr-
idine (20 cm3) was irradiated with white light from a slide
projector for 3 h. The solvent was then removed under vacuum,
and water (10 cm3) and then a solution of aqueous KPF6
(10 cm3) were added resulting in the precipitation of an orange
solid which was collected by filtration on Celite to give dark red
crystals (18 mg, 86%). 1H NMR (400 MHz, CD3CN): δ 9.11 (H,
dd, J 5.2, 1.3 Hz, HP2), 8.90 (H, dd, J 8.4 Hz, HP4), 8.59 (2H, d,
J 8.2 Hz, HB3), 8.47 (2H, ddd, J 8.2, 1.3, 0.8 Hz, HA3), 8.42 (H,
dd, J 8.4, 1.3 Hz, HP9), 8.38 (H, AB, J 9.0, HP5), 8.28 (H, t, HB4),
8.22 (H, d, HP3), 8.20 (H, AB, HP6), 8.01 (2H, ddd, J 9.2, 1.6 Hz,
HA4), 7.88–7.86 (3H, m, Hpy), 7.67 (H, dd, J 5.3 Hz, HP7), 7.64
(2H, ddd, J 5.5, HA6), 7.45 (H, dd, HP8), 7.31–7.26 (4H, m,
HA5,py). FAB-MS: m/z (calc.) 739.0 (738.7, [M Ϫ PF6]ϩ). Crys-
tals of (4)(PF6)2ؒC6H6 were obtained by vapour diffusion, in the
dark, of benzene into a solution of the product in CH3CN.
5: [Ru(terpy)(phen)(iq)][PF6]2. A mixture of [Ru(terpy)-
(phen)(CH3CN)][PF6]2 (20 mg, 0.024 mmol) and isoquinoline
(35 mg, 0.271 mmol) in degassed acetone (5 cm3) was irradiated
with white light from a slide projector for 7 h under argon.
Following purification of the crude product by column chrom-
atography (silica: MeCN–H2O–sat. KNO3(aq), 44 : 2 : 1), the
2: [Ru(terpy)(phen)(CH3CN)][PF6]2: thermal preparation. A
mixture of [Ru(terpy)(phen)Cl][PF6] (250 mg, 0.36 mmol) and
AgBF4 (116 mg, 0.60 mmol) was heated to reflux in CH3CN–
H2O (4 : 1, 250 cm3) for 3 h. The solution was filtered hot
through Celite to remove AgCl then half the solvent was
removed in vacuo. On pouring the solution into a solution of
aqueous KPF6 (200 mL) an orange solid precipitated which was
collected by filtration on Celite. This solid was purified by
column chromatography (silica: MeCN–H2O–sat. KNO3(aq)
,
44 : 2 : 1). The major, orange fraction was collected, and the
complex was precipitated by the addition of a solution of
aqueous KPF6. Following filtration the product was dried in
1
vacuo and isolated as an orange powder (256 mg, 84%). H
NMR (400 MHz, CD3CN): δ 9.97 (H, dd, J 1.2 Hz, HP2), 8.93
(H, dd, J 8.2, 1.2 Hz, HP4), 8.63 (2H, d, J 8.2 Hz, HB3), 8.46 (2H,
ddd, J 8.2, 1.3, 0.8 Hz, HA3), 8.41 (H, dd, J 8.2, HP9), 8.37–8.41
(2H, m, HP5,B4), 8.36 (H, dd, J 8.2, 5.3 Hz, HP3), 8.17 (H, d,
J 9.0, HP6), 7.99 (2H, ddd, J 8.2, 1.6 Hz, HA4), 7.67 (H, dd, J 5.3,
1.3 Hz, HP7), 7.57 (2H, ddd, J 5.5, 1.6, 0.8, HA6), 7.46 (H, dd,
J 8.2, 5.3, HP8), 7.25 (2H, ddd, J 7.6, 5.5, 1.3, HA5), 2.14 (3H, s,
CH3CN). FAB-MS: m/z (calc.) 701.0 (700.6, [M Ϫ PF6]ϩ), 555.0
(555.6, [M Ϫ 2PF6]ϩ), 515.0 (514.6, [Ru(terpy)(bpy)]ϩ). Crystals
of (2)(PF6)2ؒ2CH3CN were obtained by vapour diffusion, in the
dark, of diisopropyl ether into a solution of the product in
CH3CN.
Photochemical preparation. A solution of [Ru(terpy)(phen)-
Cl][PF6] (50 mg, 0.072 mmol) in degassed CH3CN (20 cm3) and
D a l t o n T r a n s . , 2 0 0 3 , 4 6 5 4 – 4 6 6 2
4660

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major orange fraction was collected, and the complex was pre-
cipitated by the addition of a solution of aqueous KPF6. The
precipitate was collected on Celite, redissolved in CH3CN and
dried under vacuum giving an orange powder (18 mg, 82%). 1H
NMR (500 MHz, CD3CN): δ 9.15 (H, dd, J 5.2, 1.3 Hz, HP2),
8.88 (H, dd, J 8.3, 1.3 Hz, HP4), 8.58 (2H, d, J 8.2 Hz, HB3), 8.49
(H, d, J 0.7 Hz, Hiq2), 8.46 (2H, ddd, J 8.1 Hz, HA3), 8.41 (H,
dd, HP9); 8.36 (H, AB, J 8.9 Hz, HP5), 8.25 (H, t, J 8.1 Hz, HB4),
8.19 (H, AB, HP6), 8.16 (H, dd, J 8.3, 5.2 Hz HP3), 8.00 (2H,
ddd, J 9.2, 6.7, 1.5 Hz, HA4), 7.82 (H, t, J 7.5 Hz, Hiq), 7.66–7.71
(6H, m, HP7,A6,iq), 7.44 (H, dd, J 8.2, 5.3, HP8), 7.29 (2H, ddd,
HA5). FAB-MS: m/z (calc.) 789.3 (788.7, [M Ϫ PF6]ϩ), 644.3
(643.7, [M Ϫ 2PF6]ϩ), 515.3 (514.7, [Ru(terpy)(phen)]ϩ), 322.2
(321.9, [M Ϫ 2PF6]2ϩ) Crystals of (5)2(PF6)4ؒC6H6ؒCH2Cl2 were
obtained by vapour diffusion, in the dark, of benzene into a
solution of the product in CH2Cl2.
d, J 8.9 Hz, HP5); 8.17 (H, d, J 8.1 Hz, HP7); 8.06 (H, d, J 8.9 Hz,
HP6); 7.90 (2H, td, J 7.4 Hz, HA4); 7.79 (2H, d, J 1.8 Hz, HC2);
7.73 (H, t, J 1.8 Hz, HC4); 7.64 (H, d, J 5.0 Hz, HP9); 7.53 (2H, d,
J 5.3 Hz, HA6); 7.42 (H, dd, J 8.1, 5.0 Hz, HP8); 7.25 (2H,
m, HA5); 1.50 (18H, s, HtBu). ES-MS m/z (calc.): 722.2 (721.2,
[M Ϫ 2PF6 ϩ H]ϩ); 848.2 (848.2, [M Ϫ H2O Ϫ PF6]ϩ); 380.5
(380.6, [M Ϫ 2PF6 Ϫ H2O ϩ acetone]2ϩ). Recrystallisation by
vapour diffusion in the dark, of diisopropyl ether into a solu-
tion of the product in acetone yielded crystals of (9)2(PF6)4ؒ
5C3H6O suitable for X-ray analysis.
10: [Ru(terpy*)(phen)(lut)][PF6]2: [Ru(terpy*)(phen)(CH3-
CN)][PF6]2 (24.5 mg, 0.024 mmol) was dissolved in 3,5-lutidine
(5 cm3). The solution was degassed and heated to reflux under
argon for 2 h. The lutidine was removed under vacuum, acetone
(1 cm3) and an aqueous solution of KPF6 (10 cm3) were added,
acetone was evaporated and the solid was filtered, washed with
1
6: [Ru(terpy)(phen)(dmap)][PF6]2. The same procedure as
described for 5 led to 6 after 16 h of irradiation, in 96% yield.
1H NMR (500 MHz, CD3CN): δ 9.12 (H, dd, J 5.2, 1.3 Hz,
HP2), 8.86 (H, dd, J 8.3 Hz, HP4), 8.55 (2H, d, J 8.2 Hz, HB3),
8.43 (2H, ddd, J 8.1, 3.4 Hz, HA3), 8.33–8.36 (2H, m, HP9,P5),
8.18–8.22 (2H, m, HP3,B4), 8.15 (H, AB, J 8.9, HP6), 7.95 (2H,
ddd, J 6.2, 1.5 Hz, HA4), 7.62 (H, dd, J 4.2 Hz, HP7), 7.59 (2H,
dm, J 5.5, HA6), 7.38 (H, dd, J 8.3 Hz, HP8), 7.23 (2H, ddd,
water, Et2O and vacuum dried (Yield 23 mg, 88%). H NMR
(400 MHz, acetone-d6): δ 9.39 (H, dd, J 5.4, 1.2 Hz, HP2); 9.18
(2H, s, HB3); 9.05 (H, dd, J 8.2, 1.2 Hz, HP4); 8.90 (2H, m, J 7.8
Hz, HA3); 8.57 (H, dd, J 8.2, 1.2 Hz, HP7); 8.50 (H, d, J 8.8 Hz,
HP5); 8.37 (H, dd, J 8.2, 5.4 Hz, HP3); 8.32 (H, d, J 8.8 Hz, HP6);
8.15 (2H, td, J 7.8, 1.5 Hz, HA4); 8.08 (H, dd, J 5.3, 1.2 Hz, HP9);
8.04 (2H, d, J 1.8 Hz, HC2); 8.01 (2H, dm, J 4.7 Hz, HA6); 7.78
(3H, HC4,lut2); 7.62–7.58 (2H, J 8.2, 5.3 Hz, HP8,lut4); 7.44 (2H,
m, HA5); 2.14 and 2.14 (6H, 2s, Hlut-CH3); 1.49 (18H, s, HtBu).
ES-MS m/z (calc.): 955.3 (955.3, [M – PF6]ϩ), 738.2 (738.2, [M
Ϫ 2PF6 Ϫ 3,5-lutidine ϩ Cl]ϩ), 405.0 (405.2, [M Ϫ 2PF6]2ϩ).
Crystals of (10)(PF6)2ؒC3H6OؒC4H10O were grown by slow
vapour diffusion of Et2O in an acetone solution of the complex.
11: [Ru(terpy*)(phen)Cl][PF6]: Crude Ru(terpy*)Cl3 (428 mg,
0.68 mmol), monoaqua-1,10-phenanthroline (1.04 eq, 0.708
mmol) and lithium chloride (5 eq., 3.41 mmol) and triethyl-
amine (1.5 cm3) were heated at reflux in a degassed mixture of
water (40 cm3) and ethanol (120 cm3) under argon for 4 h. A
solution of saturated aqueous KPF6 (40 cm3) was added to the
cooled dark reddish solution, the ethanol was evaporated and
the violet precipitate filtered and washed twice with water and
once with ether. Column chromatography on SiO2 (eluent acet-
one–water–saturated KNO3, 100 : 5 : 0.1) and vapour diffusion
of diethyl ether into an acetone solution of the product yielded
[Ru(terpy*)(phen)Cl][PF6] (377 mg, 62%). 1H NMR (400 MHz,
acetone-d6): δ 10.57 (H, dd, J 5.2,1.5 Hz, HP2); 9.04 (2H, s, HB3);
8.97 (H, dd, J 8.2, 1.5 Hz, HP4); 8.75 (2H, d, J 8.0 Hz, HA3); 8.45
(H, dd, J 5.2, 8.2 Hz, HP3); 8.45 (H, d, J 8.9 Hz, HP5); 8.40 (H,
dt, J 8.1, 1.1 Hz, HP7); 8.23 (H, d, J 8.9 Hz, HP6); 8.04 (2H, d,
J 1.7 Hz, HC2); 8.03 (H, dd, J 5.4, 1.1 Hz, HP9); 7.94 (2H, td,
J 8.0, 1.5 Hz, HA4); 7.75 (H, t, J 1.7Hz, HC4); 7.69 (2H, d, J 5.5
Hz, HA6); 7.47 (H, dd, J 5.4, 8.1 Hz, HP8); 7.24 (2H, ddd, J 7.6,
5.5, 1.3 Hz, HA5); 1.50 (18H, s, HtBu). ES-MS m/z (calc.): 738.2
(738.2, [M Ϫ PF6]ϩ).
HA5), 7.16 (2H, AB, J 7.4 Hz, Hdmap), 6.36 (2H, AB, Hdmap), 2.90
ϩ
(6H, s, HCH ). FAB-MS: m/z (calc.) 782.1 (781.3, [M Ϫ PF6] ),
3
636.8 (637.2, [M Ϫ 2PF6]ϩ), 515.1 (514.6, [Ru(terpy)(phen)]ϩ),
318.8 (318.4, [M Ϫ 2PF6]2ϩ). Crystals of (6)(PF6)2ؒ2CH3CN
were obtained by vapour diffusion, in the dark, of diisopropyl
ether into a solution of the product in CH3CN.
7: [Ru(terpy)(phen)(ptz)][PF6]2. The same procedure as
described for 5 led to 7 after 41 h of irradiation, in 78% yield.
1H NMR (400 MHz, CD3CN): δ 10.76 (H, dd, HP2), 8.95 (H,
dd, HP4), 8.49 (H, dd, J 8.3, 5.3 Hz, HP3), 8.40 (H, dd, J 8.1, 1.2
Hz, HP9), 8.34 (H, AB, J 8.9 Hz, HP5), 8.32–8.24 (3H, m, HB4,B3),
8.14 (H, AB, HP6), 7.90 (2H, d, HA3), 7.72 (2H, ddd, J 9.2, 7.4,
1.5 Hz, HA4), 7.47 (H, dd, J 5.2, 1.2 Hz, HP7), 7.40 (H, dd, HP8),
7.34 (2H, dm, J 5.3, HA6), 7.15 (H, s, Hptz-NH), 7.00 (2H, ddd,
J 8.3, 7.3, Hptz), 6.95 (2H, ddd, J 7.4, 5.3, 1.3 Hz, HA5), 6.52
(2H, dd, J 7.8, 1.3, Hptz), 6.42–6.37 (4H, m, Hptz), 6.52 (2H, dd,
J 7.8, 1.3, Hptz). FAB-MS: m/z (calc.) 859.3 (858.9, [M Ϫ PF6]ϩ),
713.2 (713.9, [M Ϫ 2PF6]ϩ), 515.2 (514.7, [Ru(terpy)(phen)]ϩ).
Crystals of (7)2(PF6)4ؒCH3OHؒC8H10 were obtained by vapour
diffusion, in the dark, of xylene into a solution of the product
in methanol over three months.
8: [Ru(terpy)(phen)(mqt)][PF6]3. The same procedure as
described for 5 led to 8 after 26 h of irradiation, in 80% yield.
1H NMR (400 MHz, CD3CN): δ 9.12 (H, dd, J 5.3, 1.3 Hz,
HP2), 8.99 (H, dd, J 8.3 Hz,HP4), 8.68 (2H, d, J 6.8, Hmqt), 8.59
(2H, d, J 8.1 Hz, HB3), 8.46 (2H, dm, J 8.0 Hz, HA3), 8.40 (H,
dd, J 8.3, 1.3 Hz, HP9), 8.36 (H, AB, J 8.8 Hz, HP5), 8.29 (H, t,
J 8.1 Hz, HB4), 8.20 (H, dd, HP3), 8.18 (H, AB, HP6), 8.16 (2H, d,
J 7.0, Hmqt), 8.08 (2H, dd, J 5.4, 1.5, Hmqt), 8.00 (2H, ddd, J 9.3,
7.4, 1.5 Hz, HA4), 7.65–7.61 (5H, m, HP7,A6,mqt), 7.44 (H, dd,
J 5.3 Hz, HP8), 7.28 (2H, dd, J 7.4, 5.5 HA5), 4.31 (3H, s, CH3).
FAB-MS: m/z (calc.) 976.3 (975.8, [M Ϫ PF6]ϩ), 831.3 (830.8,
[M Ϫ 2PF6]ϩ), 515.2 (514.7, [Ru(terpy)(phen)]ϩ). Crystals of
(8)4(PF6)12ؒ6CH3CNؒH2O were obtained by vapour diffusion,
in the dark, of diisopropyl ether into a solution of the product
in CH3CN.
12: [Ru(terpy*)(phen)(CH3CN)][PF6]2: [Ru(terpy*)(phen)-
Cl][PF6] (199 mg, 0.226 mmol) and AgBF4 (53.4 mg, 0.259
mmol) were dissolved in a mixture of water and acetonitrile
(1 : 4, 60 cm3). The degassed solution was heated to reflux under
argon for 4.5 h. Silver chloride was removed by filtration over
Celite, the volume of acetonitrile was reduced by evapor-
ation and a solution of saturated aqueous KPF6 (30 cm3) was
added. Evaporation of the remaining acetonitrile followed by
filtration, washing with water and vacuum drying yielded
[Ru(terpy*)(phen)(CH3CN)][PF6]2 quantitatively. 1H NMR
(300 MHz, acetone d6): δ 10.28 (H, dd, J 5.2, 1.5 Hz, HP2); 9.20
(2H, s, HB3); 9.08 (H, dd, J 8.3, 1.5Hz, HP4); 8.89 (2H, m,
J 8.0 Hz, HA3); 8.57 (H, dd, J 8.4, 1.2 Hz, HP7); 8.50 (H, d, J 8.9
Hz, HP5); 8.48 (H, dd, J 8.3, 5.2 Hz, HP3); 8.29 (H, d, J 8.9 Hz,
HP6); 8.12 (2H, td, J 8.0, 1.5 Hz, HA4); 8.09 (H, dd, J 5.3, 1.2 Hz,
HP9); 8.05 (2H, d, J 1.7 Hz, HC2); 7.87 (2H, dm, J 5.4 Hz, HA6);
7.81 (H, t, J 1.7 Hz, HC4); 7.60 (H, dd, J 5.3, 8.4 Hz, HP8); 7.38
(2H, ddd, J 5.4, 8.0, 1.2 Hz, HA5); 2.42 (3H, s, HAN–CH3); 1.50
(18H, s, HtBu). ES-MS m/z (calc.): 889.3 (889.2, [M Ϫ PF6]ϩ),
744.3 (744.3, [M Ϫ 2PF6]ϩ), 371.9 (372.1, [M Ϫ 2PF6]2ϩ).
9: [Ru(terpy*)(phen)(H2O)][PF6]2: [Ru(terpy*)(phen)Cl][PF6]
(113 mg, 0.128 mmol) and AgBF4 (10 eq, 1.28 mmol) were
dissolved in an acetone–water mixture (3 : 2, 100 cm3). The
solution was degassed and heated at reflux under argon for 3 h.
AgCl was filtered over Celite, water and an aqueous solution of
KPF6 (50 cm3) were added and acetone was evaporated. The
red solid was isolated by filtration and washed with water (89
mg, 69%). 1H NMR (300 MHz, CD2Cl2): δ 9.94 (H, d, J 4.9 Hz,
HP2); 8.82 (H, d, J 8.1 Hz, HP4); 8.57 (2H, s, HB3); 8.41 (2H, dd,
J 7.4, 0.9 Hz, HA3); 8.37 (H, dd, J 8.1 Hz, 4.9 Hz, HP3); 8.29 (H,
D a l t o n T r a n s . , 2 0 0 3 , 4 6 5 4 – 4 6 6 2
4661

View Article Online
C. Marzin, Inorg. Chem., 1983, 22, 1488–1493; (c) P. Bonneson,
J. L. Walsh, W. T. Pennington, A. W. Cordes and B. Durham,
Inorg. Chem., 1983, 22, 1761–1765.
Acknowledgements
We would like to thank the CNRS for financial support and the
European Commission for Marie Curie Postdoctoral Fellow-
ship (ERS). S. B. acknowledges support from the Region
Alsace. We thank also Johnson Matthey Inc. for a loan of
RuCl3.
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