Synthesis, characterization, absorption spectra, and luminescence properties of multinuclear species made of Ru(II) and Ir(III) chromophores

Article abstract of DOI:10.1021/ic9006108

A series of new mixed-metal Ru(II)-Ir(III) trinuclear complexes have been prepared and characterized, together with their mononuclear parents and a series of closely related dinuclear and trinuclear homometallic Ru(II) and Ir(III) species, and their absor

Full text of DOI:10.1021/ic9006108

8578 Inorg. Chem. 2009, 48, 8578–8592
DOI: 10.1021/ic9006108
Synthesis, Characterization, Absorption Spectra, and Luminescence Properties of
Multinuclear Species Made of Ru(II) and Ir(III) Chromophores
Marco Cavazzini,† Silvio Quici,*,† Chiara Scalera,† Fausto Puntoriero,‡ Giuseppina La Ganga,‡ and
Sebastiano Campagna*,‡
†Istituto di Scienze e Tecnologie Molecolari del CNR (ISTM), Via Golgi 19, I-20133 Milano, Italy, and
‡
ꢀ
Dipartimento di Chimica Inorganica, Chimica Analitica e Chimica Fisica, Universita di Messina, Via Sperone
31, I-98166 Messina, Italy
Received March 30, 2009
A series of new mixed-metal Ru(II)-Ir(III) trinuclear complexes have been prepared and characterized, together with
their mononuclear parents and a series of closely related dinuclear and trinuclear homometallic Ru(II) and Ir(III)
species, and their absorption spectra and luminescence properties (both at 77 K in rigid matrix and at room
temperature in fluid solution) have been studied. The absorption spectra and luminescence properties of the Ru(II)
species and subunits are dominated by metal-to-ligand charge-transfer (MLCT) transitions and excited states,
whereas ligand centered (LC) transitions and excited states govern the spectroscopic and photophysical properties of
most of the Ir(III) species here studied, with MLCT states playing an important role when cyclometalated Ir(III) subunits
are present. Each metal-based subunit retains in the multinuclear arrays its own spectroscopic properties, but in the
case of the mixed Ru-Ir species an efficient, additional decay channel is opened for the excited states involving the Ir-
centered subunits, that is, photoinduced energy transfer to the lower-lying MLCT state(s) involving the Ru centers.
Introduction
molecular level2 as well as of artificial systems for solar
energy conversion devices3,4 and more efficient systems for
illumination purposes (e.g., OLED).5
The study of the photophysical properties of multinuclear
metal complexes made of luminescent metal-based subunits
is a quite active field of research. Such a study, which belongs
to the general theme of supramolecular photochemistry from
a fundamental point of view,1 allows information to be
gained on intercomponent photoinduced energy and/or elec-
tron transfer processes occurring in multichromophoric,
supramolecular arrays and can give access to the preparation
of artificial species designed for controlling light at the
Whereas most of the investigations on mixed-metal multi-
nuclear systems have dealt with species containing Ru(II),
Os(II), Re(I), and Rh(III),6 multinuclear mixed-metal species
containing Ir(III)- and Ru(II)-based subunits in the same
(supra)molecular array are relatively less studied,7,8 in spite
of the impressive amount of data available on the photo-
physics of Ru(II) polypyridine complexes, whose properties
are governed by metal-to-ligand charge-transfer (MLCT)
states,1-4 and on the increasing interest in Ir(III) polyimine
compounds (including cyclometalated species), whose pho-
tophysics mainly involves MLCT and ligand-centered (LC)
*To whom correspondence should be addressed. E-mail: silvio.
quici@istm.cnr.it (S.Q.), campagna@unime.it (S.C.).
(1) (a) Balzani, V.; Scandola, F. Supramolecular Photochemistry;
Horwood: Chichester, 1991.(b) Gust, D.; Moore, T. A.; Moore, A. L. Acc. Chem.
Res. 1993, 26, 198. (c) Baranoff, E.; Collin, J.-P.; Flamigni, L.; Sauvage, J.-P.
Chem. Soc. Rev. 2004, 33, 147. (d) Ruben, M.; Rojo, J.; Romero-Salguero, F. J.;
Uppadine, L. H.; Lehn, J.-M. Angew. Chem., Int. Ed. 2004, 43, 3644. (e) Huynh,
M. H. V.; Dattelbaum, D. M.; Meyer, T. J. Coord. Chem. Rev. 2005, 249, 457.
(2) (a) Balzani, V.; Credi, A.; Venturi, M. Molecular Devices and Ma-
chines - Concepts and Perspectives for the Nanoworld, 2nd ed.; Wiley-VCH:
Weinheim, 2008.(b) Molecular Wires - From Design to Properties; De Cola, L.,
(5) (a) Welter, S.; Brunner, K.; Hofstraat, J. W.; De Cola, L. Nature 2003,
421, 54. (b) Slinker, J.; Bernards, D.; Houston, P. L.; Abruna, H. D.; Bernhard, S.;
Malliaras, G. G. Chem. Commun. 2003, 2392. (c) Sajoto, T.; Djurovich, P. J.;
Tamayo, A.; Yousufuddin, M.; Bau, R.; Thompson, M. E.; Holmes, R. J.; Forrest,
S. R. Inorg. Chem. 2005, 44, 7992.
(6) (a) Balzani, V.; Juris, A.; Venturi, M.; Campagna, S.; Serroni, S.
Chem. Rev. 1996, 96, 759. (b) Chiorboli, C.; Indelli, M. T.; Scandola, F. Top.
Curr. Chem. 2005, 257, 63.
(7) (a) Serroni, S.; Juris, A.; Campagna, S.; Venturi, M.; Denti, G.;
Balzani, V. J. Am. Chem. Soc. 1994, 116, 9086. (b) Welter, S.; Lafolet, F.;
Cecchetto, E.; Vergeer, F.; De Cola, L. ChemPhysChem 2005, 6, 2417.
(c) Sabatini, C.; Barbieri, A.; Barigelletti, F.; Arm, K. J.; Williams, J. A. G.
Photochem. Photobiol. Sci. 2007, 6, 397.
Ed.; Thematic issue, Top. Curr. Chem., 2005, 257, 1-170.
::
(3) (a) Gratzel, M. Inorg. Chem. 2005, 44, 6841. (b) Ardo, S.; Meyer, G. J.
Chem. Soc. Rev. 2009, 38, 115.
(4) (a) Balzani, V.; Campagna, S.; Denti, G.; Juris, A.; Serroni, V.;
Venturi, M. Acc. Chem. Res. 1998, 31, 26. (b) Sun, L.; Hammarstrom, L.;
Akermark, B.; Styring, S. Chem. Soc. Rev. 2001, 30, 36. (c) Conception, J. J.;
Jurss, J. W.; Templeton, J. L.; Meyer, T. J. Proc. Nat. Acad. Sci. 2008, 105,
17632. (d) Hambourger, M.; Moore, G. F.; Kramer, D. M.; Gust, D.; Moore, A. L.;
Moore, T. A. Chem. Soc. Rev. 2009, 38, 25, and references therein.
::
(8) Cavazzini, M.; Pastorelli, P.; Quici, S.; Loiseau, F.; Campagna, S.
Chem. Commun. 2005, 5266.
r
pubs.acs.org/IC
Published on Web 08/04/2009
2009 American Chemical Society

Article
Inorganic Chemistry, Vol. 48, No. 17, 2009 8579
Figure 1. Structural representation of homonuclear species investigated and their abbreviations.
excited states,5,7-10 and the efficient energy transfer processes
reported to occur in most of the published papers on mixed-
metal Ru-Ir compounds.7
properties of Ru2(2) and Ir2(2) have already been commu-
nicated.8
Results
Here we report the synthesis, characterization, and study
of the photophysicalpropertiesof a series of multinuclear Ir-
Ru compounds, together with their mononuclear parent
compounds. Moreover, four trinuclear and two dinuclear
homometallic Ru(II) and Ir(III) species are also studied.
Figure 1 and Figure 2 show the structural formulas of all
the species investigated and their abbreviations. The abbre-
viations are chosen to give immediate information on the
type and number of metal centers coordinated to the ligands,
indicated by the number in parentheses. The structural
formulas are shown in Schemes 1 and 2. Some luminescence
The Suzuki coupling between 40-(4-neopentylglyconatobo-
ronphenyl)-2,20:60,200-terpyridine (tpy-Bneo)9 and a dibromo
or tribromo aromatic derivative provided an easy and quite
versatile synthetic way to obtain several mono- and homo-
polytopic ligands (Scheme 1). However, the molar ratios
between the reacting species play an important role for the
outcome of the reaction. Indeed coupling of commercially
available 3,5-dibromotoluene with a substoichiometric
amount of tpy-Bneo (0.33 mol equiv) in the presence of
aqueousNa2CO3 as base and [Pd(PPh3)4] ascatalyst afforded
monobrominated terpyridine 1 in 77% yield after purifica-
tion by column chromatography. When the same reaction
was carried out in the presence of 3.0 mol equiv of tpy-Bneo
the bis-terpyridine 2 was isolated in 88% yield.
(9) Aspley, C. J.; Williams, J. A. G. New J. Chem. 2001, 25, 1136.
(10) Dixon, I. M.; Collin, J.-P.; Sauvage, J.-P.; Flamigni, L.; Encinas, S.;
Barigelletti, F. Chem. Soc. Rev. 2000, 29, 385.

8580 Inorganic Chemistry, Vol. 48, No. 17, 2009
Cavazzini et al.
Figure 2. Structural formulas of cyclometalated homo- and heteronuclear complexes investigated and their abbreviations.
Unfortunately our first attempts to obtain the mono- and
disubstituted derivatives 3 and 4 starting from commercially
available 1,3,5-tribromobenzene and tpy-Bneo were unsuc-
cessful. The same molar ratios adopted for the synthesis of
compounds 1 and 2 were not convenient, since in both cases a
remarkable amount of unreacted 1,3,5-tribromobenzene was
isolated, while a precipitate was formed during the reaction.
This precipitate was isolated and identified as the pure homo-
tritopic ligand 5. This behavior is not so surprising taking into
account the poor solubility of 5 in the most common organic
solvents, that could represent the effective driving force of the
process. Nevertheless it was possible to synthesize compound 3
in 72% yield by a further decrease of tpy-Bneo with respect to
1,3,5-tribromobenzene (tpy-Bneo, 0.17 mol equiv). A subse-
quent coupling reaction between terpyridine 3 and tpy-Bneo
(0.5 mol equiv) allowed the selective substitution of a second
halide, and bis-terpyridine 4 was obtained in 77% yield after
purification by column chromatography. Finally, the Pd-
catalyzed Suzuki coupling involving 1,3,5-tribromobenzene
or 1,3,5-tris(4-bromophenyl)benzene in the presence of an
excess of boronic ester (tpy-Bneo, 4 mol equiv) afforded in
good yield the star-shaped tris-terpyridines 5 and 6, respec-
tively, that directly precipitated from the reaction mixture. The
homonuclear ruthenium complexes Ru(1) and Ru2(2) were
obtained by refluxing an ethanol solution of ligands 1 and 2
with [Ru(tpy)Cl3] in the presence of N-ethylmorpholine, with
minor adjustments to the literature procedures.6a,10,11 In the
case of complexes Ru3(5) and Ru3(6), better results were
achieved using a mixture of DMF/THF (10:1 v/v) because
of the increased solubility of ligands 5 and 6 in DMF with
respect to other organic solvents. The heteroleptic iridium(III)
complexes Ir(1), Ir2(2), Ir3(5), and Ir3(6), were prepared by
reaction of the corresponding ligand with 1, 2, or 3 equiv of
[Ir(tpy)Cl3], respectively. The reactions were carried out in
refluxing ethylene glycol, followed by anion exchange with
potassium hexafluorophosphate and purification by column
chromatography on silica gel with CH3CN/0.2 M aqueous
KNO3 in the appropriate ratios, as mobile phase.
(11) Sauvage, J.-P.; Collin, J.-P.; Chambron, J.-C.; Guillerez, S.; Coudret,
C.; Balzani, V.; Barigelletti, F.; De Cola, L.; Flamigni, L. Chem. Rev. 1994,
94, 993, and references therein.

Article
Inorganic Chemistry, Vol. 48, No. 17, 2009 8581
Scheme 1. Synthesis of Terpyridine-Based Ligands 1-6
As previously reported in literature for the preparation of
dimetallic assemblies containing mixed bipyridine-terpyridine
bridging ligands,12,13 we adopted a similar divergent approach
toward the synthesis of IrRu2(10) and IrRu2(11) mixed com-
plexes. The Ir(III) chloro-bridged dimer [Ir(F2ppy)2Cl]2 was
synthesized according to the Nonoyama route by refluxing
IrCl3 3H 2O with 2.2 equiv of 2-(2,4-difluorophenyl)pyridine
3
(F2ppy) in a 3:1 mixture of 2-ethoxyethanol and water.14
(12) Arm, K. J.; Williams, J. A. G. Chem. Commun. 2005, 230.
(13) Arm, K. J.; Williams, J. A. G. J. Chem. Soc., Dalton Trans. 2006,
2172.
(14) Nonoyama, M. Bull. Chem. Soc. Jpn. 1974, 47, 767–768.

8582 Inorganic Chemistry, Vol. 48, No. 17, 2009
Cavazzini et al.
Scheme 2. Synthesis of Ir(III) Complexes Ir(10) and Ir(11)
The reaction between [Ir(F2ppy)2Cl]2 and 4,40-dibromo-2,20-
bipyridine 715 or 5,50-dibromo-2,20-bipyridine 816 in a reflux-
ing mixture of CH2Cl2/MeOH afforded the two cyclom-
etalated Ir(III) complexes Ir(7) and Ir(8) in high yields
(Scheme 2).
Compounds Ir(10) and Ir(11) were prepared by a Suzuki
cross-coupling reaction of complex Ir(7) with tpy-Bneo and of
complex Ir(8) with terpyridinyl boronic ester 9 in THF with
[Pd(PPh3)4] as the catalyst. Because of the relatively mild
conditions employed, no scrambling of Ir(III) between the
two distinct coordination sites was observed. Finally, a
further complexation step in the presence of 2 equiv of
[Ru(tpy)Cl3] in refluxing EtOH afforded the trinuclear metal
species IrRu2(10) and IrRu2(11).
The absorption spectra of all the species have been
studied in acetonitrile solution at room temperature,
whereas the luminescence properties have been investi-
gated both in the same solvent at room temperature and in
butyronitrile or EtOH/MeOH (4:1 v/v) matrices at 77 K.
The absorption spectra of the compounds containing only
Ir(III)-based subunits exhibit intense bands in the UV
region which in some cases extend into the visible region.
The absorption spectra of the compounds containing
exclusively Ru(II)-based subunits exhibit both intense
bands in the UV region and moderately intense bands in
the visible region. For the mixed-metal species, the absorp-
tion spectra appear to be the sum of the absorption bands
of the Ru(II)- and Ir(III)-based components. The molar
absorbance is in all cases roughly linearly dependent on the
number of metal-based components. Table 1 collects the
relevant absorption data of all the compounds, Figure 3
shows the absorption spectra of Ir(10) and IrRu2(10),
ꢁ
(15) Garcıa-Lago, R.; Alonso-Gomez, J.-L.; Sicre, C.; Cid, M.-M.
´
Heterocycles 2008, 75, 57.
(16) Schwab, P. F. H.; Fleischer, F.; Michl, J. J. Org. Chem. 2002, 67, 443.

Article
Inorganic Chemistry, Vol. 48, No. 17, 2009 8583
Table 1. Absorption, Photophysical, and Redox Dataa
absorption, 298 K
luminescence 298 K
luminescence 77 K
max, nm τ, μs
10
redoxd, 298 K
Eox V vs SCE Ered V vs SCE
compound
λ
max, nm (ε, M-1 cm-1
)
λ
max, nm
τ, ns
Φ
λ
Ir(1)
281 (38800)
378 (16500)
310 (125000)
486 (45300)
340 (81000)
310 (285000)
485 (109000)
279 (144000)
340 (35000)
312 (315000)
485 (105600)
252 (110100)
281 (124800)
378 (61800)
252 (120500)
281 (132700)
378 (62200)
309 (341000)
487 (154800)
310 (355000)
486 (151800)
277 (173600)
309 (281000)
486 (104800)
281 (74800)
314 (44600)
354 (32300)
378 (33200)
570
1200
0.020
490
643
þ1.41 irr.
þ1.23
e
Ru(1)
14
-1.21
Ir(10)
IrRu2(10)
540
690
1300
13
0.29
<10-4
496
645
6; 12b
15
þ1.65
e
þ1.25 [2]
þ1.65(q.rev)
þ1.64
-1.13 [2]
Ir(11)
600
150
0.08
535
640
528
8; 10b
13
e
IrRu2(11)
Ir3(5)
þ1.26 [2]
þ1.64
-1.21 [2]
573
593
3000
3000
0.007
0.007
240
þ1.42 irr.
e
Ir3(6)
548
240
þ1.44 irr.
e
Ru3(5)
Ru3(6)
Ru2(2)
680
683
683
80
80
83
<10-4
<10-4
8 ꢀ 10-5
648
13
þ1.24 [3]
þ1.26 [3]
þ1.27 [2]
-1.21 [3]
-1.22 [3]
-1.23
645
13
641 c
13c
Ir2(2)
578
2774
0.007
524 c
205 c
þ1.42 irr.
e
a In acetonitrile deaerated solution at room temperature and in EtOH/MeOH (4:1, v/v) rigid matrix at 77 K, unless otherwise stated. b biexponential
decay. c in butyronitrile rigid matrix. d Half-wave potentials; the processes are reversible, unless otherwise noted; for multielectronic processes, the
number in brackets refers to the number of electron exchanged. e Ill-behaved processes; reduction potentials cannot be assigned.
Figure 3. Absorption spectra of Ir(10) (dashed line) and IrRu2(10) (solid
line) in acetonitrile solution.
Figure 4. Absorptionspectra of Ir(11) (dashedline) and IrRu2(11) (solid
line) in acetonitrile solution.
Figure 4 shows the absorption spectra of Ir(11) and IrRu2-
(11), and Figure 5 shows the absorption spectra of Ir3(6)
and Ru3(6).
emission spectra of Ir(11) and IrRu2(11), and Figure 8
illustrates emission spectra of Ir3(5), Ir3(6), and Ru3(6).
The redox behavior of all the metal complexes has also
been investigated, in acetonitrile solution, to complement the
spectroscopic data. All the homometallic compounds exhibit
a single oxidation process (at about þ1.30 V vs SCE for the
Ru species and at more positive potentials for the Ir species),
involving the metal-centered orbital(s). For oligonuclear
homometallic species, such oxidation processes involve mul-
tiple electrons. The mixed-metalspeciesexhibittwo oxidation
processes, with the one occurring at less positive potential
being bielectronic, whereas theoneoccurring at more positive
potentials being monoelectronic in nature. On reduction,
severall ill-behaved processes take place; however, extensive
adsorption of the compounds on the electrode surface occurs.
Redox data are collected in Table 1.
All the compounds exhibit luminescence both at room
temperature in fluid acetonitrile solution and in rigid glasses
at 77 K, except Ru(1) and IrRu2(11) that emit only at low
temperature. The luminescence decays of most compounds
are monoexponential and span a time range between 13 ns
(IrRu2(10) at room temperature) and 240 μs (Ir3(5) and Ir3(6)
at 77 K). The mononuclear Ir(10) and Ir(11) compounds
exhibit biexponential decays at 77 K, with both decays in the
microsecond time range. Luminescence quantum yields,
measured in fluid solution at room temperature, range from
values lower than 10-4 for Ru(II)-containing species to 0.29
for species containing only Ir(III) chromophores. The data
for all the compounds are collected in Table 1. Figure 6 shows
emission spectra of Ir(10) and IrRu2(10), Figure 7 shows

8584 Inorganic Chemistry, Vol. 48, No. 17, 2009
Cavazzini et al.
Figure 5. Absorption spectra of Ir3(6) (dashed line) and Ru3(6) (solid
line) in acetonitrile solution.
Figure 8. Emission spectra of Ir3(5) (dashed line), Ir3(6) (dotted line),
and Ru3(6) (solid line) in EtOH/MeOH (4:1 v/v) rigid matrix at 77 K.
Figure 6. Emission spectra of Ir(10) (dashed line) and IrRu2(10) (solid
line) in EtOH/MeOH (4:1 v/v) rigid matrix at 77 K.
Figure 9. Schematic energy level diagram illustrating the energy transfer
pathway for IrRu2(10), the 3MLCT energies are obtained on the basis of
the 77 K emission spectra of the Ir(10) and IrRu2(10) species.
comparison with literature data.17,18 The band at lower
energy most likely receives also some contribution from
spin-allowed MLCT transitions involving the substituted
bipyridine ligand. In some compounds, a very weak tail is
seen on the red edge of the low-energy band, which can be
attributed to spin-forbidden MLCT transitions.
In spite of the similarity of their structure and their
cyclometalated nature, Ir(10) and Ir(11) have different
emission properties, particularly at room temperature
(Table 1, Figures 6 and 7). The room temperature emis-
sion of Ir(11) is assigned to a triplet MLCT state (namely,
Ir-to-substituted bipyridine ligand) where the acceptor
ligand of the MLCT transition should be largely deloca-
lized over the phenyls connected in meta to the bipyrid-
ine ligand, so stabilizing the MLCT states. In fact, the
analogous compound [Ir(F2ppy)2(bpy)]þ (F2ppy=2-(2,
4-difluorophenyl)pyridine anion; bpy=2,20-bipyridine),
missing the substituents on the bpy ligand, emits at higher
energies, 533 nm at room temperature and 454 nm at
77 K.7b The relatively short (150 ns) luminescence lifetime
of Ir(11) further supports this assignment.17-19 In
Figure 7. Emission spectra of Ir(11) (dashed line) and IrRu2(11) (solid
line) in EtOH/MeOH (4:1 v/v) rigid matrix at 77 K.
Discussion
Absorption Spectra and Luminescence Properties.
Mononuclear and Dinuclear Ir(III) Compounds. The ab-
sorption spectra of Ir(1), Ir(10), and Ir(11) present strong
bands in the UV region (Table 1, Figures 3 and 4), which
can be assigned to metal-perturbed spin-allowed LC tran-
sitions, on the basis of the molar absorbance, energy, and
(18) Flamigni, L.; Barbieri, A.; Sabatini, C.; Ventura, B.; Barigelletti, F.
Top. Curr. Chem. 2007, 281, 143, and references therein.
(19) Collin, J. P.; Dixon, I. M.; Sauvage, J.-P.; Williams, J. A. G.;
Barigelletti, F.; Flamigni, L. J. Am. Chem. Soc. 1999, 121, 5009.
(17) Maestri, M.; Balzani, V.; Deuschel-Cornioley, C.; von Zelewsky, A.
Adv. Photochem. 1992, 17, 1.

Article
Inorganic Chemistry, Vol. 48, No. 17, 2009 8585
Figure 10. Structural formula of Ir2Ru2(2)3.
comparison, Ir(10) emits at significantly higher energy at
room temperature, and its emission energy is intermediate
between that of Ir(11) and that of the above-mentioned
[Ir(F2ppy)2(bpy)]þ compound. Moreover, the emission
lifetime of Ir(10) is significantly longer (1.3 μs) and its
quantum yield is higher (0.29) than the respective values
of Ir(11) (150 ns and 0.08). The room temperature emis-
sion of Ir(10) is still assigned to a triplet MLCT state,
although a mixing with low-lying triplet LC states is quite
probable, but delocalization of the acceptor ligand of the
MLCT state over the para substituents of the bpy-type
coordinated site seems to be less relevant, as suggested by
the difference in emission energy between Ir(10) and
Ir(11) (Table 1). The differences in emission lifetime and
quantum yield between the two mononuclear cyclometa-
lated Ir(III) complexes can be explained by the energy gap
law.20 At 77 K in rigid matrix, both the two cyclometa-
lated compounds exhibit blue-shifted emissions com-
pared to room temperature (see Figures 6 and 7 and
Table 1), and the luminescence decay appears to be
biexponential in both cases. For both compounds we
attribute the emission to two closely lying, non-equili-
the corresponding components in the multinuclear com-
pounds.
Mono- and Dinuclear Ru(II) Compounds. All the Ru(II)
chromophores investigated in this work, either if they are
mononuclear compounds or if they are part of poly-
nuclear species, carry tridentate, terpyridine-like species.
As such, they have relatively weak photoemissive proper-
ties compared to the tris-bipyridine species, although the
absorption spectra are quite similar. Reasons for the
weak emissive properties are well-known and will not
be discussed here.6a,11,20,21 The mononuclear Ru(1) and
dinuclear Ru2(2) are in line with the general trend of bis-
terpyridine Ru(II) species (Table 1): their absorption
spectra present intense LC bands in the UV and moder-
ately intense MLCT bands in the visible, but they exhibit
weak MLCT emission properties at room temperature
(Ru2(2)) or even emissions which are below the detection
limit of our apparatus (Ru(1)). At 77 K, as usual,11,21 both
the species exhibit an intense and long-lived 3MLCT
emission.
Mixed-Metal Ir-Ru Multinuclear Compounds. The
absorption spectra of IrRu2(10) and IrRu2(11) are
roughly the sum of their isolated components spectra.
So, the visible region is dominated by moderately intense
MLCT bands involving the Ru(II) subunits and the UV
region presents spin-allowed LC bands which can be
attributed to both Ru(II)- and Ir(III)-based subunits
(Table 1, Figures 3 and 4).
The trinuclear IrRu2(10) and IrRu2(11) compounds do
not exhibit any emission at the wavelengths typical of
their corresponding Ir(III)-based components, that is,
Ir(10) and Ir(11) (Table 1, Figures 6 and 7), both at room
temperature and at 77 K. This indicates that the Ir-based
excited states are efficiently quenched by the presence of
the Ru(II) chromophores in both complexes, in both
experimental conditions. At room temperature, only
IrRu2(10) exhibits a detectable emission band, at the limit
of our equipment sensitivity, which is assigned to 3MLCT
involving the Ru(II) component(s). The excitation spec-
trum for this compound overlaps with the corresponding
absorption spectrum, so indicating that energy transfer
from the higher-lying Ir(III)-based MLCT state to the
lower-lying Ru(II)-based MLCT state is the active
quenching mechanism. The energy transfer process
is schematized in Figure 9. For analogy, we assume that
energy transfer is the Ir-based excited state quench-
ing mechanism also in the case of IrRu2(11) at room
temperature and for both compounds at 77 K, where
3
3
brated excited states, most likely of MLCT and LC
origin.
Compound Ir(1) differs from the other mononuclear
Ir(III) compounds studied in here since it is a polypyridine
complex (bis-terpyridine like) and not a cyclometalated
species. As for other Ir(III) bis-terpyridine complexes,18,19
its absorption is dominated by metal-perturbed spin-al-
lowed LC transitions and its emission originates from
a mixed 3MLCT/3LC state at room temperature and
from a metal-perturbed 3LC state at 77 K, on the basis of
the energies and lifetimes of its emission proper-
ties (Table 1) and comparison with literature data.18
The absorption spectra and luminescence properties of
Ir2(2) have been already reported8 and are here included
(Table 1) for completeness. We note that it can be
considered as derived from the mononuclear Ir(1) com-
pound; in fact, its properties are quite close to those of
Ir(1) and are interpreted in the same manner. One im-
portant information is obtained from comparison be-
tween the luminescence properties of Ir(1) and of its
dinuclear species: each chromophore is not perturbed
by the presence of the other identical one, as far as the
excited state energy and decay are concerned. This in-
dicates that the excited states are essentially localized on
the mononuclear subunits, so that the mononuclear
species Ir(1), Ir(10), and Ir(11) (and Ru(1)) can be con-
sidered as good models for the excited state properties of
(21) Campagna, S.; Puntoriero, F.; Nastasi, F.; Bergamini, G.; Balzani,
(20) Meyer, T. J. Pure Appl. Chem. 1986, 58, 1193.
V. Top. Curr. Chem. 2007, 280, 117.

8586 Inorganic Chemistry, Vol. 48, No. 17, 2009
Cavazzini et al.
only the typical Ru-based MLCT emission is observed
(Table 1). Interestingly, whereas the Ir-based emission is
quite different between Ir(10) and Ir(11), for which the
emitting MLCT state involves the central coordinating
subunit of the tritopic ligands, both at room temperature
and at 77 K, the Ru-based emission at 77 K of IrRu2(10)
and IrRu2(11), for which the emitting MLCT state in-
volves the peripheral coordinating subunit(s) of the tri-
topic ligands, are quite similar. This indicates that the
tritopic ligands Ir(10) and Ir(11) have “isolated” low-
energy orbitals mainly localized on the chelating sites and
that the electronic differences between the two ligands
essentially involve the central chelating site, coordinating
the Ir(III) center in the present compounds.
Trinuclear Homometallic Ir(III) and Ru(II) Species. The
trinuclear homometallic Ru3(5) and Ir3(5) can be consid-
ered as the fully developed homologues of the dinuclear
homometallic species Ru2(2) and Ir2(2). In fact, the brid-
ging ligand 5 derives from the bridging ligand 2 by the
addition of the third “arm”, identical to the other two that
are already present in 2. The molar absorption of the
various absorption bands confirm that each subunit is
only weakly coupled to the others, so the spectroscopic
properties of each subunit do not differ significantly on
passing from dinuclear to trinuclear systems (Table 1).
The photophysical properties of Ru3(5) and Ir3(5), in
agreement with the above reasoning, are indeed quite
similar to those of their dinuclear counterparts Ru2(2) and
Ir2(2), both at 77 K and at room temperature (Table 1). As
a consequence, the emission of the Ru(II) species is
The photophysical properties of the trinuclear mixed-
metal species discussed above, namely, the quite efficient
energy transfer process from Ir-based to Ru-based chro-
mophores, significantly differ from the previously re-
ported8 properties of Ir2Ru2(2)3, whose structural
formula is shown in Figure 10. For Ir2Ru2(2)3, energy
transfer from Ir to Ru chromophores only takes place at
77 K, whereas emission from both Ir(III)- and Ru(II)-
components is seen at room temperature, with the emis-
sion lifetime of the Ir-based chromophore (λmax=572 nm,
τ=2.9 μs)8 practically unchanged compared to the emiss-
ion lifetime of Ir2(2) (see Table 1), used as model. The
weak coupling between Ir and Ru chromophores because
of the meta arrangement of the polyphenyls contained in
the ligand 2 was claimed as the reason for the absence of
energy transfer at room temperature in Ir2Ru2(2)3.22
The difference in the occurrence of energy transfer
between the formerly studied tetranuclear species Ir2Ru2-
(2)3 and the new trinuclear compounds IrRu2(10) and
IrRu2(11) here reported warrants some discussion. There
are many differences between the tetranuclear species and
the trinuclear ones (compare structural formulas in Fig-
ures 2 and 10): (i) the nature of the Ir(III) chromophores,
that is, bis-terpyridine Ir(III) chromophores in Ir2Ru2(2)3
and cyclometalated tris-bidentate Ir(III) dyes in IrRu2(10)
and IrRu2(11); this difference also leads to an increased
MLCT character of the Ir-based excited state in the latter,
cyclometalated species, with the acceptor ligand of
the MLCT transition definitely involving the Ir-chelating
site of the tritopic bridging ligand(s); (ii) the Ir-Ru
distance is surely smaller in IrRu2(10) and IrRu2(11) than
in Ir2Ru2(2)3; (iii) the meta arrangement is not present in
IrRu2(10), so this species is expected to have a definitely
larger interchromophoric coupling than Ir2Ru2(2)3; the
meta arrangement is still present in IrRu2(11), but as
discussed above the Ir-based MLCT state for this com-
pound most likely extends over the phenyl rings directly
linked to the coordinating bpy moiety, so the meta
“defect” is bypassed by the electronic nature of the Ir-
based MLCT state. Altogether, (i)-(iii) points justify the
different behavior of the mixed-metal compounds exam-
ined here as far as the occurrence of Ir-to-Ru energy
transfer is concerned.
3
assigned to MLCT state involving the bridging ligand
as acceptor site, and the emission of the Ir(III) compound
3
is assigned to a predominantly LC state with partial
3MLCT contribution.
The compounds Ru3(6) and Ir3(6) are also similar to
Ru3(5) and Ir3(5), as the structural difference between the
two couple of trinuclear species only lies in the additional
phenyl ring contained in each bridging ligand “arm” (see
Figure 1). Also in this case, the metal-based subunits are
essentially decoupled from one another, not surprisingly.
The absorption and emission spectra of Ru3(6) are clearly
similar to those of Ru3(5), so further confirming that the
acceptor ligand of the emitting MLCT state does not
extends over the polyphenyl bridging ligand, but it only
involves the phenyl directly connected to the terpyridine
moiety. The photophysical properties of Ir3(6), on the
contrary, differ from those of Ir3(5), as far as the emission
wavelength is concerned, both at 77 K and at room
temperature (Table 1, Figure 8): in both cases, a red shift
of 20 nm is found for the emission spectra of Ir3(6). The
red-shifted emission spectra are in agreement with the
dominant LC nature of the emissive excited states of the
Ir(III) species that, differently from MLCT states, also
involve the additional phenyl ring(s) which are present
in 6 compared to 5 tritopic bridging ligands.
Redox Behavior. Oxidation processes of Ru(II) and
Ir(III) polypyridine compounds are usually metal cen-
tered.17,18,21 The redox data of systems studied here
(Table 1) are in agreement with such a common behavior,
as the oxidation potentials of the homometallic Ru(II)
species are within the potential range expected for the
metal-centered oxidation for Ru(II) complexes based on
bpy- and terpy-type ligands (þ1.20/þ1.30 V vs SCE6a,20
)
and the oxidation potentials of the homometallic Ir(III)
species take place in the potential window (þ1.30/þ
1.70 V vs SCE) expected for polypyridine and cyclome-
talated Ir(III) compounds.6a For the homometallic multi-
nuclear complexes, all the oxidation processes involve
more than one electron, in particular three electrons for
Ru3(5) and Ru3(6), which are attributed to three simulta-
neous one-electron metal-centered processes, and two
electrons for the dinuclear species Ru2(2), which are
attributed to two one-electron metal-centered oxidation
processes. Similar behavior and relative attribution holds
also for the homometallic multinuclear Ir(III) species.
The absence of oxidation splitting in the multinuclear
homometallic species confirms that each metal-centered
(22) On passing from room temperature to 77 K the excited state lifetime
of the Ir-based chromophore of Ir2Ru2(2)3 increases of 2 orders of magni-
tude, as indicated by the photophysical properties of the model Ir2(2) species
(see Table 1) and this would allow the energy transfer to successfully compete
with intrinsic decay, even in the presence of a relatively low interchromo-
phoric coupling.8

Article
Inorganic Chemistry, Vol. 48, No. 17, 2009 8587
subunit is electronically “isolated”, from the electroche-
mical viewpoint.
60 A). Column chromatography was conducted by using silica
gel Si 60, 230-400 mesh, 0.040-0.063 mm (Merck, Darmstadt,
Germany) and neutral activated aluminum oxide 50-200 μm
(Acros Organics, Geel, Belgium). Melting points have been
The mixed-metal compounds IrRu2(10) and IrRu2(11)
exhibit two oxidation processes (see Table 1); in both
compounds, the oxidation process occurring at less posi-
tive potential, which is bielectronic in nature, is assigned
to simultaneous one-electron oxidation of the terminal
Ru(II) subunits, whereas the one-electron oxidation tak-
ing place at more positive potential is assigned to the
Ir(III) subunit.
Unfortunately, the reduction pattern of all the com-
pounds is quite complicated and ill-behaved, since the
reduced compounds apparently stick on the electrode.
However, the first reduction potential is still safely mea-
sured in some cases, and is assigned to polypyridine
ligand reduction, although more precise assignment can-
not be made.
::
1
obtained by a Buchi 535 instrument and are uncorrected. H
and 13C NMR spectra were recorded on a Bruker Avance 400
(400 and 100.6 MHz, respectively); chemical shifts are indicated
in parts per million downfield from SiMe4, using the residual
proton (CHCl3=7.26 ppm; CHD2CN=1.94 ppm; CF3COOD=
11.6 ppm) and carbon (CDCl3=77.0 ppm; CD3CN=1.3 ppm;
CF3COOD=163 ppm) solvent resonances as internal reference.
Protons and carbon assignments were achieved by 13C-APT,
1
1H-1H COSY, and H-13C heteronuclear correlation experi-
ments. ESI mass spectra were obtained with an electrospray ion-
trap mass spectrometer ICR-FTMS APEX II (Bruker
Daltonics). Elemental analyses were carried out by the Depart-
ment Service of Microanalysis (University of Milan).
Absorption spectra were recorded with a JASCO V570
spectrophotometer. For Luminescence spectra a Jobin Yvon-
Spex Fluoromax 2 spectrofluorimeter was used, equipped with a
Hamamatsu R3896 photomultiplier, and the spectra were cor-
rected for photomultiplier response using a program purchased
with the fluorimeter. Luminescence lifetimes were determined
by time-correlated single-photon-counting (TCSPC) with an
Edinburgh OB900 spectrometer (light pulse: Hamamatsu PL2
laser diode, pulse width 59 ps at 408 nm; or nitrogen discharge,
pulse width at 337 nm: 2 ns). Luminescence quantum yields have
been performed by the optical dilute method.23 As quantum
yield reference, [Ru(bpy)3]2þ in aqueous deaerated solution was
used (Φ=0.028).24 Electrochemical measurements were carried
out in argon-purged acetonitrile at room temperature with an
Autolab 12 equipment interfaced to a PC. The working elec-
trode was a glassy carbon (8 mm2, Amel) electrode. The counter
electrode was a Pt wire, and the reference electrode was an SCE
separated with a fine glass frit. The concentration of the samples
was about 5ꢀ10-4 M. Tetrabutylammonium hexafluoropho-
sphate was used as supporting electrolyte and its concentration
was 0.05 M. Cyclic voltammograms were obtained at scan rates
of 20, 50, 200, and 500 mVs-1. For reversible processes, half-
wave potentials (versus SCE) were calculated as the average of
the cathodic and anodic peaks. The criteria for reversibility were
the separation of 60 mV between cathodic and anodic peaks, the
close to unity ratio of the intensities of the cathodic and anodic
currents, and the constancy of the peak potential on changing
scan rate. The number of exchanged electrons was measu-
red with differential pulse voltammetry (DPV) experiments
performed with a scan rate of 20 mV s-1, a pulse height of
75 mV, and a duration of 40 ms, and by taking advantage of the
presence of ferrocene used as the internal reference.
Experimental uncertainties are as follows: absorption max-
ima, 2 nm; molar absorption coefficient, 10%; redox potentials,
( 20 mV; emission maxima, 5 nm; excited state lifetimes, 10%.
Synthesis. 40-[4-(3-Bromo-5-methylphenyl)phenyl]-2,20:60,200-
terpyridine, 1. In a Schlenk flask placed under an atmosphere
of nitrogen, 40-(4-neopentylglyconatoboronphenyl)-2,20:60,200-
terpyridine tpy-Bneo (1.0 g, 2.37 mmol), 1,3-dibromotoluene
(1.78 g, 7.12 mmol) and [Pd(PPh3)4] (137 mg, 0.119 mmol) were
dissolved in deaerated THF (50 mL). A 2 M aqueous solution of
sodium carbonate (6 mL, 12 mmol) was added, and the mixture
was purged with nitrogen through three freeze-pump-thaw
cycles at low temperature. The reaction mixture was heated at
85 °C under vigorous stirring for 18 h. The organic solvent was
removed in vacuo, and the aqueous phase was extracted
with CH2Cl2 (3 ꢀ 20 mL). The organic phase was dried
over Na2SO4, and the solvent was removed. The product was
purified by gravimetric column chromatography over silica gel
Conclusions
A series of new mixed-metal Ru(II)-Ir(III) polynuclear
complexes have been prepared, together with their mono-
nuclear parents and a series of closely related dinuclear and
trinuclear homometallic Ru(II) and Ir(III) species. All the
new compounds have been carefully characterized by NMR
techniques, and their absorption spectra and luminescence
properties (both at 77 K in rigid matrix and at room
temperature in fluid solution) have been studied. The absorp-
tion spectra and luminescence properties of the Ru(II) species
and subunits are dominated by MLCT transitions and
excited states, whereas LC transitions and excited states
govern the spectroscopic and photophysical properties of
most of the Ir(III) species here studied, with MLCT states
playing important role when cyclometalated Ir(III) subunits
are present. The results also show that each metal-based
subunit retains in the multinuclear arrays its own spectro-
scopic properties, but in the case of the mixed Ru-Ir species
an additional decay channel is opened for the excited states
involving the Ir-centered subunits, that is, photoinduced
energy transfer to the lower-lying MLCT state(s) involving
the Ru centers. The structure of the bridging ligand plays a
key role in making such energy transfer process an effective
decay route: we propose that a meta arrangement of the
polyphenyl moieties which constitute the polytopic, bridging
ligand framework can significantly reduce the interchromo-
phoric electronic coupling so making the energy transfer
process too slow to compete with the intrinsic decay of the Ir-
based chromophore.
Work is in progress in our laboratories to design novel
multinuclear heterometallic luminescent species, also includ-
ing different metal centers, and to investigate the possible
non-covalent interactions of the compounds containing large
aromatic moieties with additional chromophores and/or
donor and acceptor species.
Experimental Section
Material and Methods. All available chemicals were pur-
chased from commercial sources and were used without any
further purification. Solvents were purified by using standard
methods and dried if necessary. Air- and moisture-sensitive
reactions were performed under usual inert atmosphere techni-
ques. Thin layer chromatography (TLC) was conducted on
plates precoated with silica gel Si 60-F254 (Merck, Darmstadt,
Germany) and aluminum oxide (Fluka, medium pore diameter
(23) Crosby, G. A.; Demas, J. N. J. Phys. Chem. 1971, 75, 991.
(24) Nakamaru, N. Bull. Chem. Soc. Jpn. 1982, 55, 2697.

8588 Inorganic Chemistry, Vol. 48, No. 17, 2009
Cavazzini et al.
(CH2Cl2/MeOH 95:5), to yield 1 as a pale white solid (824 mg,
77%). mp 254 °C. 1H NMR (400 MHz, CDCl3, 30 °C): δ 8.78 (s,
MeOH 200:1), to yield 4 as a white solid (824 mg, 77%). mp0294
0
°C. 1H NMR (400 MHz, CDCl3, 30 °C): δ 8.81 (s, 4H, tpyH3 ,5 ),
0
0
00
00
2H, tpyH3 ,5 ), 8.75 (br d, 2H, J = 4.0 Hz, tpyH6,6 ), 8.69 (d, 2H,
8.75 (br d, 4H, J = 4.0, tpyH6,6 ), 8.70 (d, 4H, J = 8.0 Hz,
00
00
J =8.0 Hz, tpyH3,3 ), 7.99 [d, 2H, 0J0 = 8.3 Hz, Ar(A)H2,6], 7.89
tpyH3,3 ), 8.04 (d, 4H, J=8.3 Hz, tphH3,5), 7.89 (dt, 4H, J=7.07,
00
0
0
(dt, 2H, J = 8.0, 2.0 Hz, tpyH4,4 ), 7.69 [d, 2H, J = 8.3 Hz,
1.8 Hz, tpyH4,4 ), 7.85 (m, 1H, tphH2 ), 7.82 (m, 2H, tphH4 ,6 ),
7.79 (d,040 H, J=8.3 Hz, tphH2,6), 7.37 (br dd, 4H, J=7.7, 4.0 Hz,
00
Ar(A)H3,5], 7.61 [br s, 1H, Ar(B)H2], 7.35-7.39 [m, 4H, tpyH5,5
,
Ar(B)H4 and Ar(B)H6], 2.43 (s, 3H, CH3); 13C NMR (101 MHz,
tpyH5,5 ). 13C NMR (101 MHz, CDCl3, 30 °C): δ 156.4 (q),
00
00
CDCl3, 30 °C): δ 156.4 (q), 156.1 (q), 149.8 (q), 149.3 (tpyC6,600),
142.5 (q), 140.7 (q), 140.6 (q), 138.0 (q), 137.0 (tpyC4,4 ),
131.3 [Ar(B)C4], 127.9 [Ar(A)C2,6], 127.800 [Ar(A)C3,5], 127.4
[Ar(B)C2], 126.8 [Ar(B)C6], 124.0 (tpyC5,5 ), 122.9 (q), 121.6
156.2 (q), 149.7 (q), 149.3 (tpyC6,6 ), 143.2 (q), 140.4 (q), 138.4
00
0
0
(q), 137.0 (tpyC4,4 ), 129.4 (tphC4 ,6 ), 128.1 (tphC3,5), 127.9
0
00
(tphC2,6), 125.0 (tphC2 ), 0 1024.1 (tpyC5,5 ), 123.6 (q), 121.6
00
(tpyC3,3 ), 118.9 (tpyC3 ,5 ). ESI-MS (770.2, calcd for
C48H31BrN6) m/z (%): 773.2 (100), 771.2 (95.4), 772.2 (50),
774.2 (47.3) [MþH]þ; 795.2 (100), 793.2 (89.5), 796.2 (52.6),
794.2 (47.4) [MþNa]þ. Anal. found: C 74.80, H 4.06, N 11.01%;
Calcd for C48H31BrN6: C 74.71, H 4.05, N 10.87%.
00
0
0
(tpyC3,3 ), 118.9 (tpyC3 ,5 ), 21.5 (CH3). ESI-MS (477.1, calcd for
C28H20BrN3) m/z (%): 478.1 (100), 480.1 (97.6) [MþH]þ; 500.1
(100), 502.1 (97.6) [MþNa]þ; 979.1 (100), 980.1 (53.3)
[2MþNa]þ. Anal. found: C 70.49, H 4.22, N 8.79%; Calcd for
C28H20BrN3: C 70.30, H 4.21, N 8.78%.
1,3,5-Tris[4-(2,20:60,200-terpyridin-40-yl)phenyl]benzene, 5. Com-
pound 5 was prepared following an analogous procedure as
described for 1, from tpy-Bneo (400 mg, 0.96 mmol), 1,3,5-
tribromobenzene (75 mg, 0.24 mmol), [Pd(PPh3)4] (27 mg,
0.023 mmol), and 0.2 M aqueous Na2CO3 (8.3 mL, 1.66 mmol)
in THF (40 mL). The product precipitated from the reaction
mixture and was isolated by filtration on a fritted glass. The
collected solid was washed with THF (10 mL), water (20mL), and
finally Et2O (20 mL) to afford tris-terpyridine 5 as a pale white
solid (167 mg, 70%). mp 374 °C. 1H NMR (40000 MHz,
CF3COOD, 30 °C): δ 9.26 (br d, 6H, J=8.0 Hz, tpyH6,6 0 ), 9.08
4,400-Bis(2,20:60,200-terpyridin-40-yl)-50-methyl-1,10:30100-terph-
enyl, 2. Compound 2 was prepared following an analogous
procedure as described for 1, from tpy-Bneo (320 mg,
0.759 mmol), 1,3-dibromotoluene (64 mg, 0.256 mmol),
[Pd(PPh3)4] (20 mg, 0.017 mmol), and 0.2 M aqueous Na2CO3
(6.5 mL, 1.3 mmol) in THF (35 mL). The isolation of the
product was performed as described above, and the residue
was dissolved in CH2Cl2 (2 mL) and MeOH (10 mL) was added.
After concentration of this solution, compound 2 was collected
as a pale white solid (160 mg, 88%) by filtration. mp 214 0°C; 1H
00
0
0
(d, 6H, J=8.0 Hz, tpyH3,3 ), 8.94-9.01 (m, 12H, tpyH3 ,5 and
NMR (400 MHz, CDCl3, 30 °C): δ 8.81 (s, 4H, tpyH3 ,5 ), 8.070 6
00
4,400
5,500
tpyH ), 8.34 (m, 6H, tpyH ), 8.14-8.21 [m, 15H, Ar(A)H3,5
,
(br d, 4H, J=4.4 Hz, tpyH6,6 ), 8.68 (d, 4H, J=8.0 Hz, tpyH3,3 ),
Ar(A)H2,6, and Ar(B)H2,4,6]. 13C NMR (101 MHz, CF3COOD,
8.03 (d, 4H, J=8.4 Hz, tphH3,5), 7.88 (dt, 4H, J=8.8, 2.8 Hz,
00
30 °C): δ 156.8 (q), 149.6 (tpyC4,4 ), 148.4 (q), 148.2 (q), 145.6 (q),
00
tpyH4,4 ), 7.81 (d, 4H, J = 8.4 Hz, tphH2,6), 7.75 (br s, 1H,
00
146.6 (tpyC6,6 ), 142.7 (q), 135.3 (q), 129.7 [Ar(A)C2,6], 129.3
0
0
0
00
tphH2 ), 7.50 (br s, 2H, tphH4 ,6 ), 7.34-7.37 (m, 4H, tpyH5,5 ),
00
00
(tpyC5,5 ), 128.8 [Ar(A)C3,5], 127.0 [Ar(B)C2,4,6], 126.0 (tpyC3,3 ),
2.54 (s, 3H, CH3). 13C NMR (101 MHz, CDCl3, 30 °C): δ 156.4
0
0
124.4 (tpyC3 ,5 ). ESI-MS (999.4, calcd for C69H45N9) m/z (%):
1000.4 (100), 1001.4 (75.3), 1002.4 (23.4) [MþH]þ; 500.7 (100),
501.2 (74), 501.7 (24.4) [Mþ2H]2þ. Anal. found: C 83.04, H 4.56,
N 12.63%; Calcd for C69H45N9: C 82.86, H 4.54, N 12.60%.
1,3,5-Tris{4-[4-(2,20:60,200-terpyridin-40-yl)phenyl]phenyl}ben-
zene, 6. Compound 6 was prepared following an analogous
procedure as described for 1, from tpy-Bneo (320 mg,
0.76 mmol), 1,3,5-tris-(4-bromophenyl)benzene (103 mg,
0.19 mmol), [Pd(PPh3)4] (23 mg, 0.020 mmol) and 0.2 M
aqueous Na2CO3 (5.7 mL, 1.14 mmol) in THF (40 mL). The
product precipitated from the reaction mixture and was isolated
by filtration on a fritted glass. The collected solid was washed
with THF (15 mL), water (20 mL), and finally Et2O (20 mL) to
afford tris-terpyridine 6 as a white solid (180 mg, 77%). 1H
00
(q), 156.1 (q), 149.9 (q), 149.3 (tpyC6,6 ), 142.0 (q), 141.3
00
(q), 139.2 (q), 137.6 (q), 137.0 (tpyC4,4 ), 127.9 (tphC2,6
40,60
5,500
20
and tphC3,5), 127.4 (tphC ), 124.0 (tpyC ), 123.4 (tphC ),
00
0
0
121.5 (tpyC3,3 ), 118.9 (tpyC3 ,5 ), 21.8 (CH3). ESI-MS (706.3,
calcd for C49H34N6) m/z: 707.3 (100) [MþH]þ; 729.3 [MþNa]þ.
Anal. found: C 83.48, H 4.84, N 11.86%; Calcd for C49H34N6: C
83.26, H 4.85, N 11.89%.
40-[4-(3,5-Dibromophenyl)phenyl]-2,20:60,200-terpyridine, 3. Com-
pound 3 was prepared following an analogous procedure as de-
scribed for 1, from tpy-Bneo (500 mg, 1.19 mmol), 1,3,5-
tribromobenzene (2.24 g, 7.14 mmol), [Pd(PPh3)4] (68 mg,
0.059 mmol) and 1.0 M aqueous Na2CO3 (4 mL, 4.0 mmol) in
THF (30 mL). The isolation of the product was performed as
described above, and the residue was purified by gravimetric column
chromatography over silica gel (CH2Cl2/petroleum ether, 4:1),
to yield 3 as a yellow solid (470 mg, 72%). mp 294 °C; 1H NMR
0
0
NMR (400 MHz, CDCl3, 30 °C): δ 8.82 (s, 6H, tpyH3 ,5 ), 8.75
00
00
(br d, 6H, J=5.0 Hz, tpyH6,6 ), 8.70 (d, 6H, J=8.0 Hz, tpyH3,3 ),
8.05 [d, 6H, J=8.4 Hz, Ar(A)H3,5], 7.94 [s, 3H, Ar(C)H2,4,6],
0
0
(400 MHz, CDCl3, 30 °C): δ 8.78 (s, 2H, tpyH3 ,5 ), 8.75 (br d, 2H,
7.83-7.92 [m, 24H, Ar(A)H2,6, Ar(B)H2,6, A0r0(B)H3,5 and
00
00
J = 4.0 Hz, tpyH6,6 ), 8.69 (d, 2H, J = 8.0 Hz, tpyH3,3 ), 8.01
00
tpyH4,4 ], 7.37 (dd, 6H, J=7.7, 5.0 Hz, tpyH5,5 ). 13C NMR
[d, 2H, J = 8.3 Hz, Ar(A)H2,6], 7.90 (dt, 2H, J = 7.7, 1.7 Hz,
00
tpyH4,4 ], 7.73 [d, 2H, J=1.7 Hz, Ar(B)H2,6], 7.67-7.69 [m, 3H,
(101 MHz, CDCl3, 30 °C): δ 156.4 (q), 156.2 (q), 149.9 (q), 149.3
00
00
(tpyC6,6 ), 142.1 (q), 141.4 (q), 140.5 (q), 139.8 (q), 137.6 (q),
Ar(A)H3,5 and Ar(B)H4], 7.37 (dd, 2H, J=7.7, 4 Hz, tpyH5,5 ); 13
C
00
137.0 (tpyC4,4 ), 128.0 [Ar(A)C3,5 and Ar(A)C2,6], 127.8
[Ar(B)C2,6 or Ar(B)C3,5], 127.7 [Ar(B)C2,6 or Ar(B)C3,5], 1250.3
NMR (101 MHz, CDCl3, 30 °C): δ 156.4 (q), 156.3 (q), 149.6
00
(q), 149.3 (tpyC6,6 ), 144.2 (q), 139.1 (q), 138.7 (q), 137.1
00
00
0
00
[Ar(C)C2,4,6], 124.0 (tpyC5,5 ), 121.5 (tpyC3,3 ), 118.9 (tpyC3 ,5 ).
ESI-MS (1227.5, calcd for C87H57N9) m/z (%): 1229.5 (100),
1228.5 (95.7), 1230.5 (42.8) [MþH]þ; 614.7 (100), 615.2 (96.7),
615.7 (41.8) [Mþ2H]2þ; 410.2 (100), 410.5 (96.2), 410.8 (40.9)
[Mþ3H]3þ. Anal. found: C 85.28, H 4.69, N 10.24%; Calcd for
C87H57N9: C 85.06, H 4.68, N 10.26%.
(tpyC4,4 ), 133.1 [Ar(B)C4], 129.1 [Ar(B)C2,6], 128.2 [Ar(A)C2,6],
00
00
127.8 [Ar(A)C3,5], 124.1 (tpyC5,5 ), 123.6 (q), 121.6 (tpyC3,3 ), 118.9
0
0
(tpyC3 ,5 ). ESI-MS (541.0, calcd for C27H17Br2N3) m/z (%): 543.0
(100), 541.0 (51), 545.0 (49) [MþH]þ; 566.0 (100), 564.0 (51), 568.0
(49) [MþNa]þ. ]þ. Anal. found: C 59.80, H 3.16, N 7.75%; Calcd
for C27H17Br2N3: C 59.69, H 3.15, N, 7.73%.
4,400-Bis(2,20:60,200-terpyridin-40-yl)-50-bromo-1,10:30100-terph-
enyl, 4. Compound 4 was prepared following an analogous
procedure as described for 1, from tpy-Bneo (150 mg,
0.356 mmol), terpyridine 3 (387 mg, 0.712 mmol), [Pd(PPh3)4]
(40 mg, 0.035 mmol), and 0.5 M aqueous Na2CO3 (4.3 mL,
2.15 mmol) in THF (35 mL). The isolation of the product was
performed as described above, and the residue was purified by
gravimetric column chromatography over silica gel (CH2Cl2/
[(tpy)Ru(1)][PF6]2, Ru(1). [Ru(tpy)Cl3] (55 mg, 0.12 mmol)
was added to a solution of 1 (48 mg 0.10 mmol) in MeOH
(20 mL). A few drops of N-ethylmorpholine were added, and the
mixture was heated at reflux under nitrogen for 5 h, after which
it was cooled and filtered. A saturated aqueous solution of
NH4PF6 was added to the filtrate to give a red precipitate that
was collected by filtration and purified by chromatography
(SiO2, MeCN/0.2 M aqueous KNO3 100:1), to afford Ru(1)

Article
Inorganic Chemistry, Vol. 48, No. 17, 2009 8589
00
00
(45 mg, 43%) after anionic exchange with hexafluorophosphate
as a red microcrystalline solid. H NMR (400 MHz, CD3CN,
(5)tpyH3,3 ], 8.53 (br d, 6H,0 J = 8.0 Hz, tpyH3,3 ), 8.37-8.48
[m, 18H, (5)Ar(A)H2,6, tpyH4 , (5)Ar(A)H3,500 and (5)Ar(B)H2,4,6],
1
0
0
00
30 °C): 0δ 9.05 [s, 2H, (1)tpyH3 ,5 ], 8.77 (d, 2H, J = 8.2 Hz,
7.93-8.01 [m, 12H, (5)tpyH4,4 and tpyH4,4 ], 7.48 [br d, 6H, J=
0
00
00
00
tpyH3 ,5 ), 8.67 [br d, 2H, J=8.0 Hz, (1)tpyH3,3 ], 8.50 (br d, 2H,
5.6 Hz, (5)tpyH6,6 ], 7.3900(br d, 6H, J=5.6 Hz, tpyH6,6 ), 7.19-
00
0
00
J=8.0 Hz, tpyH3,3 ), 8.42 (t, 1H, J=8.2 Hz, tpyH4 ), 8.31 [d, 2H,
7.23 [m, 12H, (5)tpyH5,5 and tpyH5,5 ]. 13C NMR (101 MHz,
CD3CN, 30 °C): δ 159.2 (q), 159.1 (q), 156.6 (q), 156.4 (q), 153.6
J=8.5 Hz, Ar(A)H2,6], 8.01 00[d, 2H, J=8.5 Hz, Ar(A)H3,5],
00
00
6,600
7.90-7.97 [m, 4H, (1)tpyH4,4 and tpyH4,4 ], 7.83 [br s, 1H,
(tpyC6,6 ),010 53.4 [ (5)tpyC ], 148.7 (q), 143.5 (q), 142.6 (q), 139.1
0
0
0
Ar(B)H2], 7.66 [br s, 1H, Ar(B)H4], 7.51 [br s, 1H, Ar(B)H6],
[(5)tpyC4,4 and tpyC4,4 ], 137.4 (q), 136.9 (tpyC4 ), 129.7
00 00
00
7.43 [br d, 2H, J=5.6 Hz, (1)tpyH6,6 ], 7.35 (br d, 2H, 0J0 =5.6
[Ar(A)C2,6], 129.5 [Ar (A)C3,5], 128.5 [0(05)tpy C5,5 and tpyC5,5 ],
00
00
00
Hz, tpyH6,6 ), 7.16-7.20 [m, 4H, (1)tpyH5,5 and tpyH5,5 ], 2.48
126.9 [Ar(B)C2,4,6], 125.6 [(5)0tpyC3,3 ], 125.5 (tpyC3,3 ), 124.8
0
0
0
(s, 3H, CH3). 13C NMR (101 MHz, CD3CN, 30 °C): δ 159.1 (q),
(tpyC3 ,5 ), 122.6 [(5)tpyC3 ,5 ]. ESI-MS (2874.2, calcd for
00
159.0 (q), 156.5 (q), 156.4 (q), 153.5 (tpyC6,6 ), 153.4
C
114H78F36N18P6Ru3) m/z (%): 813.1 (100) [M-3PF6]3þ; 573.3
00
[(1)tpyC6,6 ], 148.6 (q), 142.7 (q), 142.5 (q), 142.4 (q),
(100) [M-4PF6]4þ; 429.7 (100) [M-5PF6]5þ; 333.9 (100) [M-
6PF6]6þ. Anal. found: C 47.74, H 2.75, N 8.79%; Calcd for
C114H78F36N18P6Ru3: C 47.66, H 2.74, N 8.78%.
00
00
00
00
139.1 [(1)tpyC4,4 or tpyC4,4 ], 139.0 [(1)tpyC4,4 or tpyC4,4 ],
0
137.2 (q), 136.8 (tpyC4 ), 132.5 [Ar(B)C6], 129.3 [Ar(A)C2,6],
00
00
129.17 [Ar(A)C3,5], 128.5 [(1)tpyC5,5 and tpyC5,5 ], 128.0
{[(tpy)Ru]3(6)}[PF6]6, Ru3(6). [Ru(tpy)Cl3] (115 mg, 0.26 mmol
was added to a suspension of 6 (86 mg, 0.07 mmol) in a mixture of
THF (5 mL) and DMF (50 mL) containing a few drops of
N-ethylmorpholine. The resulting suspension was heated at reflux
under nitrogen for 24 h, after which a clear red solution was
obtained. Thiswascooledandconcentratedbyevaporationunder
reduced pressure. After addition of a saturated aqueous solution
of NH4PF6, water (80 mL) was added to facilitate the precipita-
tion of a deep red solid. This was collected by filtration and
purified by chromatography (SiO2, MeCN/0.2 M aqueous KNO3
95:5), to afford Ru3(6) (108 mg, 50%) after anionic exchange with
hexafluorophosphate as a red crystalline solid. 0 10H NMR
(400 MHz, CD3CN, 30 °C): δ 9.11 [s, 6H, (6)tpyH3 ,5 ], 8.78 (d,
00
[Ar(B)C2], 127.9 [Ar(B)C4], 125.5 [(1)tpyC3,3 ], 125.4
00
0
0
0
0
(tpyC3,3 ), 124.7 (tpyC3 ,5 ), 123.5 (q), 122.5 [(1)tpyC3 ,5 ], 21.3
(CH3). ESI-MS: (1102.0, calcd for C43H31BrF12N6P2Ru) m/z
(%): 959.0 (100), 957.0 (95.8), 958.0 (62.3), 956.0 (58.4) [M-
PF6]þ; 407.0 (100), 406.0 (89.0), 406.5 (59.3), 405.5 (59.2) [M-
2PF6]2þ. Anal. found: C 46.78, H 2.87, N 7.63%; Calcd for
C43H31BrF12N6P2Ru: C 46.84, H 2.86, N 7.62%.
[(tpy)Ru(2)Ru(tpy)][PF6]4, Ru2(2). [Ru(tpy)Cl3] (62 mg,
0.14 mmol) was added to a suspension of 2 (49 mg, 0.07 mmol)
in EtOH (20 mL) containing a few drops of N-ethylmorpholine.
The mixture was heated at reflux under nitrogen for 24 h, after
which it was cooled and filtered. A saturated aqueous solution
of NH4PF6 was added to the filtrate to give a red precipitate that
was collected by filtration and purified by chromatography
(SiO2, MeCN/0.2 M aqueous KNO3 100:1), to afford Ru2(2)
(109 mg, 80%) after anionic exchange with hexafluoropho-
0
0
00
6H, J=8.2 Hz, tpyH3 ,5 ), 8.71 [br d, 6H, J=8.0 Hz, (6)tpyH3,3 ],
00
8.52 (br d, 6H, J=8.0 Hz, tpyH3,3 ), 8.43 (t, 3H, J=8.2 Hz,
0
tpyH4 ), 8.39 [d, 6H, J = 8.5 Hz, (6)Ar(A)H2,6], 8.07-8.20
[m, 21H, (6)Ar(A)H3,5
,
(6)Ar(B)H2,4
,
(6)0A0 r(B)H3,5 and
00
sphate as a red microcrystalline solid.0 1H NMR (400 MHz,
(6)Ar(C)H2,4,6], 7.93-7.99 [m, 12H, (6)tpyH4,4 and tpyH4,4 ],
0
00
CD3CN, 30 °C): δ 9.10 [s, 4H, (2)tpyH3 ,5 ], 8.77 (d, 4H, J=8.2
7.48 [br d, 6H, J=5.6 Hz, (6)tpyH6,6 ], 7.3800(br d, 6H, J=5.6 Hz,
0
0
00
00
00
Hz, tpyH3 ,5 ), 8.70 [br d, 4H, J=8.0 Hz, (2)tpyH3,3 ], 8.52 (br d,
tpyH6,6 ), 7.18-7.22 [m, 12H, (6)tpyH5,5 and tpyH5,5 ]. 13C
00
0
4H, J=8.0 Hz, tpyH3,3 ), 8.43 (t, 2H, J=8.2 Hz, tpyH4 ), 8.39
[d, 4H, J = 8.5 Hz, (2)Ar(A)H2,6], 8.20 [d, 4H, J = 8.5 Hz,
(2)Ar(A)H3,5], 8.09 [br s, 1H, (2)Ar(B)H4], 7.92-7.99 [m, 8H,
NMR (101 MHz, CD3CN,0030 °C): δ 159.2 (q), 159.1 (q), 156.5
00
(q), 156.4 (q), 153.6 (tpyC6,6 ), 153.4 [(6)tpyC6,6 ], 148.7 (q), 143.2
00
00
(q), 142.8 (q), 141.5 (q), 140.1 (q), 139.1 [(6)tpyC4,4 and tpyC4,4 ],
00
00
0
(2)tpyH4,4 and tpyH4,4 ], 7.79 [0b0 r s, 2H, (2)Ar(B)H2,6], 7.47
[br d, 4H, J=5.6 Hz, (2)tpyH6,6 ], 7.38 (br d, 4H, J0=0 5.6 Hz,
136.9 (q), 136.8 (tpyC4 ), 129.4 [Ar(A)C2,6], 129.2 [Ar(A)C3,5],
00
129.0 [Ar(B)C2,6], 128.7 [Ar(B)C3,5], 128.5 [(6)tpyC5,5 and
00
00
00
00
tpyH6,6 ), 7.17-7.22 [m, 8H, (2)tpyH5,5 and tpyH5,5 ], 2.64 (s,
tpyC5,5 ], 126.1 [Ar(C)C2,4,6], 125.6 0[(6)tpyC3,3 ], 125.5
00
0
0
0
3H, CH3). 13C NMR (101 MHz, CD3CN, 30 °C): δ 159.2 (q),
(tpyC3,3 ), 124.8 (tpyC3 ,5 ), 122.5 [(6)tpyC3 ,5 ]. ESI-MS (3102.3,
calcd for C132H90F36N18P6Ru3) m/z (%): 888.8 (100) [M-
00
159.1 (q), 156.5 (q), 156.4 (q), 153.6 (tpyC6,6 ), 153.4
00
[(2)tpyC6,600], 148.8 (q), 143.8 (q), 141.6(0q0 ), 140.9 (q), 139.1
3PF6]3þ; 630.6 (100) [M-4PF6]4þ; 475.3 (100) [M-5PF6]5þ
;
00
00
[(2)tpyC4,4 or tpyC4,4 ], 139.0 [(2)tpyC4,4 or tpyC4,4 ], 136.9
372.9 (100) [M-6PF6]6þ. Anal. found: C 51.22, H 2.92, N
8.14%; Calcd for C132H90F36N18P6Ru3: C 51.12, H 2.93, N
8.13%.
0
(q), 136.8 (tpyC4 ), 129.3 [Ar(A)C2,6 and0A0 r(A)C3,5], 128.8 [Ar-
00
00
(B)C2,6], 128.5 [(2)tpyC5,5 and0 tpyC5,5 ], 125.6 [(2)tpyC3,3 ],
00
0
125.4 0(tpyC3,3 ), 124.7 (tpyC3 ,5 ), 124.1 [Ar(B)C4], 122.5 [(2)-
[(tpy)Ir(1)][PF6]3, Ir(1). A suspension of [Ir(tpy)Cl3] (112 mg,
0.21 mmol) and 1 (101 mg 0.21 mmol) in ethylene glycol (20 mL)
was heated under nitrogen for 2 h. After cooling at room
temperature, a saturated aqueous solution of NH4PF6 was
added. The precipitated solid was filtered, washed with water,
and finally purified by column chromatography (SiO2, MeCN/
0.2 M aqueous KNO3, 100:1 to 4:1), to yield after anionic
exchange with hexafluorophosphate Ir(1) (70 mg, 25%) as a
yellow crystalline solid. 1H NMR (400 MHz, CD3CN, 30 °C): δ
0
tpyC3 ,5 ], 21.7 (CH3). ESI-MS (1956.1, calcd for C79H56-
F24N12P4Ru2) m/z (%): 833.1 (100), 832.6 (96.1), 833.6 (82.3),
834.1 (78.5) [M-2PF6]2þ; 507.1 (100), 506.7 (93.3), 507.4 (76.3),
506.1 (75.5) [M-3PF6]3þ; 344.1 (100), 343.8 (92.6), 344.3 (77.8),
343.6 (72.6) [M-4PF6]4þ. Anal. found: C 48.43, H 2.90, N
8.57%; Calcd for C79H56F24N12P4Ru2: C 48.53, H 2.89, N
8.60%.
{[(tpy)Ru]3(5)}[PF6]6, Ru3(5). [Ru(tpy)Cl3] (106 mg, 0.24 mmol)
was added to a suspension of 5 (77 mg, 0.08 mmol) in a mixture
of THF (5 mL) and DMF (50 mL) containing a few drops of
N-ethylmorpholine. The resulting suspension was heated at
reflux under nitrogen for 24 h, after which a clear red solution
was obtained. This was cooled and concentrated by evaporation
under reduced pressure. After addition of a saturated aqueous
solution of NH4PF6, water (80 mL) was added to facilitate the
precipitation of a deep red solid. This was collected by filtration
and purified by chromatography (SiO2, MeCN/0.2 M aqueous
KNO3 95:5), to afford Ru3(5) (126 mg, 55%) after anionic
exchange with hexafluorophosphate as a red crystalline solid. 1H
0
0
0
0
9.12 [s, 2H, (1)tpyH3 ,5 ], 8.86 (dd, 2H, J=9.2, 7.6 Hz, tpyH3 ,5 ),
0
8.77 (dd, 1H, J=9.2, 7.6 Hz, tpyH4 ), 8.74 [br d, 2H, J=8.0 Hz,
00
00
(1)tpyH3,3 ], 8.59 (br d, 2H, J=8.0 Hz, tpyH3,3 ), 8.32 [d, 2H, J=
00
8.5 Hz, (1)Ar(A)H2,6], 8.19-8.26 [m, 4H, (1)tpyH4,4 and
00
tpyH4,4 ], 8.07 [d, 2H, J = 8.5 Hz, (1)Ar(A)H3,5], 7.84 [br s,
00
1H, (1)Ar(B)H2], 7.70 [br d, 2H, J=5.6 Hz, (1)tpyH6,6 ], 7.67 [br
6,600
s, 1H, (1)Ar(B)H4], 7.60 (br d, 2H, J=5.6 Hz, tpyH ), 7.47-
00
00
7.52 [m, 5H, (1)Ar(B)H6, (1)tpyH5,5 and tpyH5,5 ], 2.48 (s,
3H, CH3). 13C NMR (101 MHz, CD3CN, 30 °C): δ 159.0 (q),
00
158.9 (q), 156.4 (q), 155.8 (q), 155.6 (q), 154.5 (tpyC6,6 ), 154.3
00
0
00
00
[(1)tpyC6,6 ], 144.7 (tpyC4 ), 143.9 [(1)tpyC4,4 or tpyC4,4 ],
0
0
00
00
NMR (400 MHz, CD3CN, 30 °C): δ 9.14 [s, 6H, (5)tpyH3 ,5 ], 8.78
143.8 [(1)tpyC4,4 or tpyC4,4 ], 142.5 00 (q), 142.3 (q), 135.6
0
0
00
(d, 6H, J = 8.2 Hz, tpyH3 ,5 ), 8.71 [br d, 6H, J = 8.0 Hz,
(q), 132.9 [Ar(B)C6], 130.8 [(1)tpyC5,5 and tpyC5,5 ], 130.0

8590 Inorganic Chemistry, Vol. 48, No. 17, 2009
[Ar(A)C2,6], 129.4 [Ar(A)C3,5], 128.4 [(1)tpy C3,3 and tpyC3,3 ],
Cavazzini et al.
00
00
0.2 M aqueous KNO3, 100:1 to 4:1), to yield after anionic
exchange with hexafluorophosphate Ir2(6) (76 mg, 25%) as a
yellow crystalline solid. 1H NMR (400 MHz, CD3CN, 30 °C): δ
0
0
128.2 [Ar(B)C2], 128.1 [Ar(B)C4], 127.6 (tpyC3 ,5 ), 125.1
0
0
[(1)tpyC3 ,5 ], 123.5 (q), 21.3 (CH3). ESI-MS (1338.0, calcd for
C43H31BrF18IrN6P3) m/z: 1193.1 (100), 1195.1 (71.5), 1194.1
(52.3), 1196.1 (33) [M-PF6]þ; 524.1 (100), 525.1 (71.4), 524.6
(47.2), 522.6 [M-2PF6]2þ; 301.1 (100), 301.7 (63.8), 301.4 (42),
300.4 (37.7) [M-3PF6]3þ. Anal. found: C 38.65, H 2.35, N 6.27%;
Calcd for C43H31BrF18IrN6P3: C 38.58, H 2.33, N 6.28%.
0
0
0
0
9.18 [s, 6H, (6)tpyH3 ,5 ], 8.89 (br d, 6H, J=8.0 Hz, tpyH3 ,5 ),
00
0
8.78-8.81 [m, 9H, (6)tpyH3,3 and tpyH4 ], 8.62 (br d, 6H, J=8.0 Hz,
00
tpyH3,3 ), 8.41 [d, 6H, J=8.4 Hz, (6)Ar(A)H2,6], 8.08-8.28 [m,
33H, (6)Ar(A)H3,5, (6)0A0 r(B)H2,6, (6)Ar(B)H3,5, (6)Ar(C)H2,4,6
,
00
00
(6)tpyH4,4 and tpyH4,4 ], 7.75 [br d, 6H, J=5.6 Hz, (6)tpyH6,6 ],
00
7.64 (br d, 6H, J = 5.6 Hz, tpyH6,6 ), 7.50-7.56 [m, 12H,
[(tpy)Ir(2)Ir(tpy)][PF6]6, Ir2(2). A suspension of [Ir(tpy)Cl3]
(64 mg, 0.12 mmol) and 2 (42 mg 0.06 mmol) in ethylene glycol
(20 mL) was heated under nitrogen for 2 h. After cooling at
room temperature, a saturated aqueous solution of NH4PF6
was added. The precipitated solid was filtered, washed with
water, and finally purified by column chromatography (SiO2,
MeCN/0.2 M aqueous KNO3, 100:1 to 4:1), to yield after
anionic exchange with hexafluorophosphate Ir2(2) (101 mg,
69%) as a yellow crystalline solid. 1H NMR (400 MHz, CD3CN,
00
00
(6)tpyH5,5 and tpyH5,5 ]. 13C NMR (101 MHz, CD3CN,
30 °C): δ 159.0 (q), 158.9 (q), 156.5 (q), 155.7 (q), 155.6 (q),
00
00
0
154.4 (tpyC6,6 ),00154.3 [(6)tpyC6,6 ], 144.7 (tpyC4 ), 144.6 (q),
4,400
00
00
143.9 [(6)tpyC4,4 or tpyC4,4 ], 143.8 [(6)tpyC4,4 or tpyC ],
00
142.7 (q), 141.8 (q), 139.7 (q), 135.3 (q), 130.9 [(6)tpyC5,5 or
00
00
00
tpyC5,5 ], 130.8 [(6)tpyC5,5 or tpyC5,5 ], 130.2 [Ar (A)C2,6], 129.2
[Ar(A)C3,5], 129.2 [Ar(B)C2,6], 128.9 0 [Ar(B)C3,5], 128.5 [(6)-
00
00
0
tpyC3,3 and tpyC3,3 ], 127.6 [tpyC3 ,5 ], 126.2 [Ar(C)C2,4,6],
0
0
125.1 [(6)tpyC3 ,5 ]. ESI-MS (3810.3, calcd for C132
H90F54Ir3N18P9) m/z 1124.8 (100) [M-3PF6]3þ; 807.4 (100)
-
0
0
30 °C): δ 9.17 [s, 4H, (2)tpyH3 ,5 ], 8.88 (dd, 4H, J=9.2, 7.6 Hz,
0
0
0
00
tpyH3 ,5 ), 8.76-8.81 [m, 6H, tpyH4 and (2)tpyH3,3 ], 8.61 (br d,
[M-4PF6]4þ; 617.1 (100) [M-5PF6]5þ; 489.9 (100) [M-6PF6]6þ
;
00
4H, J=8.0 Hz, tpyH3,3 ), 8.40 [d, 4H, J=8.5 Hz, (2)Ar(A)H2,6],
399.2 (100) [M-7PF6]7þ; 331.2 (100) [M-8PF6]9þ; 278.3 (100)
00
00
8.22-8.27 [m, 12H, (2)tpyH4,4 , tpyH4,4 and (2)Ar(A)H3,5],
[M-9PF6]9þ. Anal. found: C 41.52, H 2.39, N 6.64%; Calcd for
8.11 [br s, 1H, (2)Ar(B)H4], 7.82 [br s, 2H, (2)Ar(B)H2,6], 7.74 [br
00
d, 4H, J = 5.6 Hz, (2)tpyH6,6 ], 7.61 (br d, 4H, J = 5.6 Hz,
C
132H90F54Ir3N18P9: C 41.62, H 2.38, N 6.62%.
00
00
00
tpyH6,6 ), 7.49-7.54 [m, 8H, (2)tpyH5,5 and tpyH5,5 ], 2.64 (s,
[Ir(F2ppy)2(7)][PF6], Ir(7). Bis-(μ)-chlorotetrakis-(2-(2,4-difl-
uorophenyl) pyridinatoC2,N)diiridium(III) [Ir(F2ppy)2Cl]2
(239 mg, 0.20 mmol) was added to a solution of 4,40-dibromo-
2,20-bipyridine 7 (163 mg, 0.52 mmol) dissolved in CH2Cl2
(60 mL) and MeOH (30 mL). The mixture was stirred at reflux
for 18 h, after which a saturated aqueous solution of NH4PF6
was added. The solvent was removed in vacuo, and the residue,
dissolved in CH2Cl2 (50 mL), was washed with water (3ꢀ20 mL).
The organic phase was dried over Na2SO4, and the solvent was
evaporated. The product was purified by gravimetric column
chromatography over silica gel (CH2Cl2/MeOH, 100:1), to
3H, CH3). 13C NMR (101 MHz, CD3CN, 30 °C): δ 159.0 (q),
00
158.9 (q), 156.5 (q), 155.8 (q), 155.6 (q0), 154.4 (tpyC6,6 ), 154.3
00
00
[(2)tpyC6,6 ], 145.2 (q), 144.7 (tpyC4 ), 143.9 [(2)tpyC4,4 or
00
00
00
tpyC4,4 ], 143.8 [(2)tpyC4,4 or tpyC4,400 ], 141.3 (q), 141.0 0(0 q),
00
135.4 (q), 130.9 [(2)tpyC5,5 or tpyC5,5 ], 130.8 [(2)tpyC5,5 or
00
tpyC5,5 ], 130.1 [Ar(A)C2,060 ], 129.5 [Ar(A)C3,5], 129.2 [Ar-
00
0
0
(B)C2,6], 128.4 [(02)tpyC3,3 and tpyC3,3 ], 127.6 (tpyC3 ,5 ),
0
125.1 [(2)tpyC3 ,5 ], 124.4 [Ar(B)C4], 21.7 (CH3). ESI-MS
(2428.2, calcd for C79H56F36Ir2N12P6) m/z (%): 1069.1 (100),
1068.1 (85.2), 1068.6 (71.8), 1069.6 (68.1) [M-2PF6]2þ; 664.4
(100), 663.8 (85.9), 664.8 (76.8), 664.1 (75.3) [M-3PF6]3þ. Anal.
found: C 39.21, H 2.34, N 6.94%; Calcd for C79H56F36Ir2N12P6:
C 39.09, H 2.33, N 6.92%.
1
afford Ir(7) (370 mg, 90%) as a yellow solid. H NMR (400
MHz, CD2Cl2, 30 °C): δ 8.59 (d, 2H, JH-H=1.8 Hz, bpyH3),
=
8.31 (dd, 2H, JH-H = 8.4 Hz, pyH3), 7.86 (br t, 2H, JH-H
8.4 Hz, pyH4), 7.80 (d, 2H, JH-H=5.8 Hz, bpyH6), 7.70 (dd, 2H,
H-H=1.8 and 5.8 Hz, bpyH5), 7.53 (br d, 2H, JH-H=6.0 Hz,
{[(tpy)Ir]3(5)}[PF6]9, Ir3(5). A suspension of [Ir(tpy)Cl3] (191 mg,
0.36 mmol) and 5 (120 mg 0.12 mmol) in ethylene glycol (40 mL)
was heated under nitrogen for 2 h. After cooling at room tempera-
ture, a saturated aqueous solution of NH4PF6 was added. The
precipitated solid was filtered, washed with water, and finally
purified by column chromatography (SiO2, MeCN/0.2 M aqueous
KNO3, 100:1 to 9:1), to yield after anionic exchange with hexa-
fluorophosphate Ir2(5) (129 mg, 30%) as a yellow crystalline solid.
J
pyH6), 7.11 (ddd, 2H, JH-H=1.6, 6.0, and 8.4 Hz, pyH5), 6.61
(ddd, 2H, JH-H=2.4 Hz, JH-F=9.1 and 12.1 Hz, dfphH3), 5.71
(dd, 2H, JH-H =2.4 Hz, JH-F =8.4 Hz, dfphH5). 13C NMR
(101 MHz, CD2Cl2, 30 °C): δ 164.3 (dd, JC-F=12.7 and 259.0
Hz, q), 164.3 (d, JC-F=7.0 Hz, q), 161.7 (dd, JC-F=12.7 and
259.0, q), 155.7 (q), 152.6 (d, JC-F=6.7 Hz, q), 151.3 (bpyC6),
149.2 (pyC6), 139.9 (pyC4), 137.7 (q), 132.9 (bpyC5), 129.3
(bpyC3), 128.0 (q), 124.4 (pyC5), 124.3 (pyC3), 114.4 (d,
JC-F = 18.0 Hz, dfphC5), 99.8 (t, JC-F = 26.7 Hz, dfphC3).
ESI-MS (1029.9, calcd for C32H18Br2F10IrN4P) m/z 886.9 (100),
884.9 (83.9), 888.9 (41.7), 887.9 (33.9) [M-PF6]þ. Anal. found:
C 37.34, H 1.77, N 5.41%; Calcd for C32H18Br2F10IrN4P: C
37.26, H 1.76, N 5.43%.
0
0
1H NMR (400 MHz, CD3CN, 30 °C): δ 9.21 [s, 6H, (5)tpyH3 ,5 ],
0
0
8.90 (dd, 006H, J = 8.8, 7.6 Hz, tpyH3 ,5 ), 8.77-8.82 [m, 9H,
0
00
(5)tpyH3,3 and tpyH4 ], 8.62 (br d, 6H, J=8.4 Hz, tpyH3,3 ), 8.49
[d, 6H, J=8.8 Hz, (5)Ar(A)H3,5], 8.42-8.44 [m, 9H, (5)Ar(A)H2,6
00
and (5)Ar(B)H2,4,6], 8.27 [dt, 6H, J=1.6, 8.8 Hz, (5)tpyH4,4 ], 8.23
00
[dt, 6H, J = 1.6, 8.8 Hz, tpyH4,4 ], 7.76 [br d, 006H, J = 5.6 Hz,
00
(5)tpyH6,6 ], 7.63 (br d, 6H, 0J0 =5.6 Hz, tpyH6,6 ), 7.50-7.56 [m,
00
12H, (5)tpyH5,5 and tpyH5,5 ]. 13C NMR (101 MHz, CD3CN, 30
°C): δ 159.0 (q), 158.9 (q), 156.5 (q), 155.7 (q), 155.5 (q), 153.4
[Ir(F2ppy)2(8)][PF6], Ir(8). The same experimental procedure
applied for Ir(7) has been followed to yield Ir(8) (349 mg, 85%)
as a yellow solid. 1H NMR (400 MHz, CD2Cl2, 30 °C): δ 8.53 (d,
2H, JH-H = 8.8 Hz, bpyH3), 8.32-8.36 (m, 4H, pyH3 and
bpyH4), 7.99 (d, 2H, JH-H =2.4 Hz, bpyH6), 7.88 (br t, 2H,
00
00
0
(tpyC6,6 ), 153.3 [(5)tpyC6,6 ], 144.8 (q), 144.7 (tpyC4 ),
00
00
143.8 [(5)tpyC4,4 and tpyC4,4 ], 142.3 (q), 135.8 (q), 00 130.9
[Ar(A)C2,6], 130.7 [Ar(A)C3,5], 130.2 129.8 [(5)tpyC5,5 and
00
00
00
0
0
tpyC5,5 ], 128.5 [(5)tpyC3,3 ], 128.40 (tpyC3,3 ), 127.6 (tpyC3 ,5 ),
J
H-H=8.0 Hz, pyH4), 7.50 (br d, 2H, JH-H=6.8 Hz, pyH6), 7.11
0
127.4[Ar(B)C2,4,6], 125.2 [(5)tpyC3 ,5 ]. ESI-MS (3582.2, calcd for
(ddd, 2H, JH-H=1.6, 6.8, and 8.0 Hz, pyH5), 6.62 (ddd, 2H,
C
114H78F54Ir3N18P9) m/z: 1048.8 (100) [M-3PF6]3þ; 750.6 (100)
J
J
H-H=2.4 Hz, JH-F=9.1 and 12.1 Hz, dfphH3), 5.68 (dd, 2H,
H-H=2.4 Hz, JH-F=8.4 Hz, dfphH5). 13C NMR (101 MHz,
[M-4PF6]4þ; 571.1 (100) [M-5PF6]5þ; 451.9 (100) [M-6PF6]6þ
.
Anal. found: C 38.34, H 2.19, N 7.02%; Calcd for C114H78-
F54Ir3N18P9: C 38.23, H 2.20, N 7.04%.
CD2Cl2, 30 °C): δ 164.3 (dd, JC-F=12.6 and 227.0 Hz, q), 164.3
(d, JC-F=6.7 Hz, q), 161.6 (dd, JC-F=12.6 and 227.0 Hz, q),
154.0 (q), 152.0 (d, JC-F=6.7 259.0 Hz, q), 151.8 (bpyC6), 149.2
(pyC6), 143.6 (bpyC4), 140.0 (pyC4), 128.0 (q), 126.9 (bpyC3),
126.0 (q), 124.6 (pyC3), 124.4 (pyC5), 114.4 (d, JC-F=18.0 Hz,
dfphC5), 100.0 (t, JC-F =26.7 Hz, dfphC3). ESI-MS (1029.9,
calcd for C32H18Br2F10IrN4P) m/z 886.9 (100), 884.9 (83.9),
888.9 (41.7), 887.9 (33.9) [M-PF6]þ. Anal. found: C 37.30, H
{[(tpy)Ir]3(6)}[PF6]9, Ir3(6). A suspension of [Ir(tpy)Cl3]
(127 mg, 0.24 mmol) and 6 (98 mg 0.08 mmol) in ethylene glycol
(30 mL) was heated under nitrogen for 8 h. After cooling at
room temperature, a saturated aqueous solution of NH4PF6
was added. The precipitated solid was filtered, washed with
water, and finally purified by chromatography (SiO2, MeCN/

Article
Inorganic Chemistry, Vol. 48, No. 17, 2009 8591
1.78, N 5.42%; Calcd for C32H18Br2F10IrN4P: C 37.26, H 1.76,
N 5.43%.
H 3.52, N 8.40%; Calcd for C88H58F10IrN10P: C 63.34, H 3.50,
N 8.39%.
[Ir(F2ppy)2(10)][PF6], Ir(10). In a Schlenk flask placed under
an atmosphere of nitrogen, 40-(4-neopentylglyconatoboronphe-
nyl)-2,20:60,200-terpyridine tpy-Bneo (65 mg, 0.15 mmol), iridium
complex Ir(7) (53 mg, 0.05 mmol), and [Pd(PPh3)4] (6 mg,
5.1 μmol) were dissolved in deaerated THF (10 mL). A 0.07 M
aqueous solution of sodium carbonate (3.0 mL, 0.21 mmol) was
added to the mixture, that was purged with nitrogen through
three freeze-pump-thaw cycles at low temperature. The solu-
tion was heated at 85 °C under vigorous stirring for 18 h. After
cooling, the organic solvent was removed by evaporation under
reduced pressure, CH2Cl2 (20 mL) was added, and the organic
phase was washed and separated. The organic phase was dried
over Na2SO4, and the solvent was evaporated. The product was
purified by gravimetric column chromatography over alumi-
num oxide (CH2Cl2/EtOH, 500:1) to afford Ir(10) (73 mg, 72%)
as a yellow solid. 1H NMR (400 MHz, CD2Cl2, 30 °C): δ 9.12 (br
{[(tpy)Ru]2Ir(10)}[PF6]5, IrRu2(10). [Ru(tpy)Cl3] (26 mg,
0.06 mmol) was added to a suspension of Ir(10) (45 mg,
0.03 mmol) in EtOH (20 mL) containing a few drops of N-
ethylmorpholine. The mixture was heated at reflux under nitro-
gen for 24 h, after which it was cooled and filtered. A saturated
aqueous solution of NH4PF6 was added to the filtrate to give a
red precipitate that was collected by filtration and purified by
chromatography (SiO2, MeCN/0.2 M aqueous KNO3 9:1), to
afford IrRu2(10) (41 mg, 80%) after anionic exchange with
hexafluorophosphate as a red microcrystalline solid. 1H NMR
(400 MHz, CD3CN, 30 °C): δ0 9.20 (br d, 2H, JH-H=1.6 Hz,
0
bpyH30 ), 9.09 [s, 4H, (10)tpyH3 ,5 ], 8.76 (d, 4H, JH-H=8.0 Hz,
0
00
tpyH3 ,5 ), 8.69 [br d, 4H, JH-H=8.0 Hz, (10)tpyH3,3 ], 8.41-
00
0
8.52 [m, 12H, tpyH3,3 , Ar(A)H2,6, tpyH4 and pyH3], 8.38 [d,
4H, JH-H =8.4 Hz, Ar(A)H3,5], 8.19 (d, 2H, JH-H =5.6 Hz,
00
00
bpyH6], 7.91-8.03 [m, 12H, bpyH5, tpyH4,4 , (10)tpyH4,4
0
0
00
s, 2H, bpyH030), 8.82 (s, 4H, tpyH3 5 ), 8.68-8.71 (m, 8H, tpyH3,3
and pyH4], 7.87 (br d, 2H, JH-H =6.0 Hz, pyH6), 7.45 [br d,
00
and tpyH6,6 ), 8.37 (br d, 2H, JH-H=8.8 Hz, pyH3), 8.08-8.16
4H, JH-H=5.6 Hz, (10)tpyH6,6 ], 7.37 [br d, 4H, JH-H=5.6 Hz,
00
00
00
[m, 10H, bpyH6, Ar(A)H3,5 and Ar(A)H2,6], 7.85-7.93 (m, 6H,
tpyH6,6 ], 7.16-7.24 [m, 10H, tpyH5,5 , (10)tpyH5,5 and pyH5],
6.79 (ddd, 2H, JH-H=2.4 Hz, JH-F=9.6, 12.8 Hz, dfphH3), 5.87
(dd, 2H, JH-H=2.0 Hz, JH-F=8.4 Hz, dfphH5). 13C NMR (101
MHz, CD3CN, 30 °C): δ 165.9 (dd, JC-F=12.5 and 222.0 Hz, q),
165.9 (d, JC-F=7.0 Hz, q), 162.3 (dd, JC-F=12.3 and 218.0 Hz,
00
tpyH4,4 and pyH4), 7.83 (dd, 2H, JH-H = 1.6 and 5.6 Hz,
bpyH5), 7.69 (br d, 2H, JH-H = 6.0 Hz, pyH6), 7.38 (m, 4H,
00
tpyH5,5 ), 7.12 (ddd, 2H, JH-H=1.6, 6.0, and 8.8 Hz, pyH5),
6.65 (ddd, 2H, JH-H=2.4 Hz, JH-F=9.1 and 12.1 Hz, dfphH3),
5.82 (dd, 2H, JH-H=2.4 Hz, JH-F=8.4 Hz, dfphH5). 13C NMR
(101 MHz, CD2Cl2, 30 °C): δ 164.3 (dd, JC-F = 12.7 and
q), 159.1 (q), 157.3 (q), 010 56.6 (q), 156.3 (q),00155.7 (d, JC-F
=
6.6 Hz, q), 153.6 (tpyC6,6 ), 153.4 [(10)tpyC6,6 ], 151.5 (q), 150.7
00
259.0 Hz, q), 164.3 (d, JC-F = 7.0 Hz, q), 161.7 (dd, JC-F
=
(bpyC6), 147.9 (q), 140.7 (pyC4), 140.0 (q), 010 39.2 [tpyC4,4 or
00
00
12.7 and 259.0, q), 155.7 (q), 152.600(d, JC-F=6.7 Hz, q), 154.2
(10)tpyC4,4 ], 139.1 [tpyC4,4 or (10)tpyC4,4 ], 138.4 (q), 136.9
0
(q), 151.1 (bpyC6), 149.6 (tpyC6,6 ), 149.2 (pyC6), 149.1 (q),
(tpyC4 )0,0 129.9 [Ar(A)C2,6], 129.8 [Ar(A)C3,5], 129.1 (q), 128.6
00
00
00
00
141.7 (q), 139.7 (py4), 137.1 (tpyC4,4 ), 136.1 (q), 128.8
[tpyC5,5 or (10)tpyC5,5 ], 1020 8.5 [tpyC5,5 or (10)tpyC5,5 ], 127.4
00
00
(Ar(A)C2,6 and Ar(A)C3,5), 126.5 (bpyC5), 124.4 (tpyC5,5 and
(bpyC5), 125.6 [(10)tpyC3,3 ], 125.5 (tpyC3,3 ), 125.1 (pyC3 and
00
0
0
0
0
pyC3),0 124.2 (py5), 123.4 (bpyC3), 121.5 (tpyC3,3 ), 119.1
pyC5), 124.8 (tpyC3 ,5 ), 124.1 (bpyC3), 122.7 [(10)tpyC3 ,5 ],
114.8 (d, JC-F = 18.5 Hz, dfphC5), 99.9 (t, JC-F = 27.2 Hz,
dfphC3). ESI-MS (2738.2, calcd for C104H68F34IrN16P5Ru2)
m/z 1224.1 (100) [M-2PF6]2þ; 767.8 (100) [M-3PF6]3þ; 539.6
(100) [M-4PF6]4þ. Anal. found: C 45.74, H 2.51, N 8.20%;
Calcd for C104H68F34IrN16P5Ru2: C 45.64, H 2.50, N 8.19%.
{[(tpy)Ru]2Ir(11)}[PF6]5, IrRu2(11). [Ru(tpy)Cl3] (44 mg,
0.1 mmol) was added to a suspension of Ir(11) (83 mg, 0.05
mmol) in EtOH (35 mL) containing a few drops of N-ethylmor-
pholine. The mixture was heated at reflux under nitrogen for
24 h, after which it was cooled and filtered. A saturated aqueous
solution of NH4PF6 was added to the filtrate to give a red
precipitate that was collected by filtration and purified by
chromatography (SiO2, MeCN/0.2 M aqueous KNO3 9:1), to
afford IrRu2(11) (106 mg, 73%) after anionic exchange with
hexafluorophosphate as a red crystalline solid. 1H NMR
0
(tpyC3 ,5 ), 114.4 (d, JC-F =18.0 Hz, dfphC5), 99.6 (t, JC-F
=
26.7 Hz, dfphC3). ESI-MS (1488.3, calcd for C74H46F10IrN10P)
m/z 1343.3 (100), 1344.3 (73.2), 1341.3 (52.1), 1342.3 (43.2) [M-
PF6]þ. Anal. found: C 59.72, H 3.14, N 9.39%; Calcd for
C74H46F10IrN10P: C 59.71, H 3.12, N 9.41%.
[Ir(F2ppy)2(11)][PF6], Ir(11). This compound was prepared
following an analogous procedure as described for Ir(10), from
tpy-Bneo (131 mg, 0.27 mmol), iridium complex Ir(8) (90 mg,
0.09 mmol), [Pd(PPh3)4] (10 mg, 8.7 μmol), and 0.2 M aqueous
Na2CO3 (2.6 mL, 0.52 mmol) in THF (10 mL). The isolation of
the product was performed as described above, and the residue
was purified by gravimetric column chromatography over alu-
minum oxide (CH2Cl2/EtOH, 500:1) to afford Ir(11) (105 mg,
70%) as a yellow solid. 1H NMR (400 MHz, CD2Cl2, 30 °C): δ
0
0
00
00
8.83 (s, 4H, tpyH3 5 ), 8.65-8.73 (m, 10H, tpyH3,3 , tpyH6,6 and
0
0
bpyH3), 8.47 (br d, 2H, JH-H=7.6 Hz, bpyH4), 8.38 (br d, 2H,
(400 MHz, CD3CN, 30 °C): δ 9.07 [s, 4H, (11)tpyH3 ,5 ], 8.77
0
0
J
H-H=2.4 Hz, pyH3), 8.32 (d, 2H, JH-H=1.6 Hz, bpyH6), 8.01
(d, 4H, JH-H=8.0 Hz, tpyH3 ,5 ), 8.68-8.73 [m, 6H, bpyH3 and
00
00
[d, 4H, JH-H=8.4 Hz, Ar(A)H2,6], 7.85-7.93 (m, 6H, tpyH4,4
and pyH4), 7.70-7.72 [m, 6H, Ar(A)H3,5 and pyH6], 7.61 [br s,
2H, Ar(B)H], 7.43 [br s,020 H, Ar(B)H], 7.38 (ddd, 4H, JH-H=1.4,
4.8, and 7.6 Hz, tpyH5,5 ), 7.31 [br s, 2H, Ar(B)H], 7.13 (br t, 2H,
(11)tpyH3,3 ], 8.61 (dd, 2H, JH-H=2.0, 8.4 Hz, bpyH4), 8.51 (d,
00
0
4H, JH-H=8.0 Hz, tpyH3,3 ), 8.34-8.45 [m, 8H, tpyH4 , pyH3
00
00
and Ar(A)H2,6], 7.89-8.02 [m, 16H, tpyH4,4 , (11)tpyH4,4
,
pyH4, bpyH6 and Ar(A)H3,5], 7.80 [br s, 2H, Ar(B)H2 or 4 or 6],
J
H-H=7.2 Hz, pyH5), 6.73 (ddd, 2H, JH-H=2.4 Hz, JH-F=9.2
7.64 [br s, 2H, Ar(B)H2 or 4 or 6], 7.48-7.50 [m, 4H, pyH6 and
00
and 13.2 Hz, dfphH3), 5.91 (dd, 2H, JH-H=2.4 Hz, JH-F=8.0
Ar(B)H2 or 4 or 6], 7.45 [br d, 4H, JH-H=5.6 Hz, (11)tpyH6,6 ],
00
Hz, dfphH5), 2.48 (s, 6H, CH3). 13C NMR (101 MHz, CD2Cl2,
7.38 (br d, 4H, JH-H=5.6 Hz, tpyH6,6 ), 7.17-7.25 [m, 10H,
00
00
30 °C): δ 164.5 (dd, JC-F=10.8 and 230.0 Hz, q), 164.5 (d, JC-F=
4.0 Hz, q), 161.8 (dd, JC-F = 11.8 and 259.0 Hz, q), 156.5
(d, JC-F = 5.7 Hz, q), 154.4 (q), 154.1 (q), 149.8 (q), 149.6
pyH5, tpyH5,5 and (11)tpyH5,5 ], 6.90 (m, 2H, dfphH3), 5.98
(m, 2H, dfphH5), 2.54 (s, 6H, CH3). 13C NMR (101 MHz,
CD3CN, 30 °C): δ 164.9 (dd, JC-F=12.2 and 225.0 Hz, q), 164.7
(d, JC-F=7.0 Hz, q), 162.4 (dd, JC-F=12.3 and 218.0 Hz, q),
00
(tpyC6,6 ), 149.3 (pyC3), 148.7 (bpyC5), 141. Nine (q), 141.3 (q),
140.1 (q), 140.8 (q), 139.8 (pyC4), 138.6 (q), 137.9 (bpyC4), 137.3
161.2 (q), 159.1 (q), 156.4 (d, JC-F=15.00H0 z, q), 155.6 (q), 155.0
00
00
(tpyC4,4 ), 135.1 (q), 129.8 [Ar(B)C], 128.2 [Ar(A)C2,6 or Ar-
(A)C3,5], 127.9 [Ar(A)C2,6 or Ar(A)C3,500], 127.2 [Ar(B)C ], 125.5
(bpyC3), 124.3 (pyC3, pyC5 and tpyC5,5 ), 123.0 [Ar(B)C ], 121.5
(q), 153.6 (tpyC6,6 ), 153.3 [(11)tpyC6,6 ], 151.1 (bpyC5), 149.8
(pyC3), 148.6 (q), 142.9 (q), 141.7 (q), 141.5 (q), 141.4 (q), 140.6
00
00
(pyC4), 139.1 [(11)tpyC4,4 and tpyC4,4 ], 138.4 (bpyC4), 137.3
00
0
0
0
(tpyC3,3 ), 118.9 (tpyC3 ,5 ), 114.8 (d, JC-F=17.0 Hz, dfphC5),
99.5 (t, JC-F=28.0 Hz, dfphC3), 21.6 (CH3). ESI-MS (1668.4,
calcd for C88H58F10IrN10P) m/z 1523.4 (100), 1524.4 (86.8),
1522.4 (41.8), 1521.4 (40.9) [M-PF6]þ. Anal. found: C 63.49,
(q), 136.8 (tpyC4 ), 136.4 (q), 130.3 [Ar(B)C2 or 4 or 6], 129.4
[Ar(A)C2,6], 129.1 [Ar(A)C3,5], 128.5 [Ar(B)C2
,
or
4 or 6
00
00
(11)tpyC5,5
,
tpyC5,5 and pyC6], 126.0 (bpyC3), 125.6
00 00 00
00
[tpyC3,3 or (11)tpyC3,3 ], 125.5 [tpyC3,3 or (11)tpyC3,3 ],

8592 Inorganic Chemistry, Vol. 48, No. 17, 2009
Cavazzini et al.
0
0
125.1 (pyC5), 124.7 (tpyC3 ,5 ), 123.8 [Ar(B)C2 or 4 or 6], 122.6
supramolecolare delle proprieta fotoniche e dispositivistica
innovativa per optoelettronica” and by FIRB RBNE033KMA
“Molecular compounds and hybrid nanostructured materials
with resonant and non-resonant optical properties for photonic
devices”.
ꢀ
0
0
[(11)tpyC3 ,5 ], 115.2 (d, JC-F=18.3 Hz, dfphC5), 99.8 (t, JC-F
26.2 Hz, dfphC3), 21.6 (CH3). ESI-MS (2918.3, calcd for
=
C
118H80F34IrN16P5Ru2) m/z 827.8 (100) [M-3PF6]3þ; 584.6
(100) [M-4PF6]4þ; 438.7 (100) [M-5PF6]5þ. Anal. found: C
48.47, H 2.77, N 7.70%; Calcd for C118H80F34IrN16P5Ru2: C
48.58, H 2.76, N 7.68%.
Supporting Information Available: Relevant absorption,
emission and excitation spectra of the metal complexes, cyclic
voltammograms of selected compounds, and proton NMR
spectra of all the free ligands and metal complexes (44
pages). This material is available free of charge via the Internet
at http://pubs.acs.org.
Acknowledgment. This work was supported by MIUR
(PRIN project), the University of Messina (PRA pro-
jects), PROMO CNR-INSTM, “Nanostrutture organiche,
organometalliche, polimeriche e ibride: ingegnerizzazione