R. Ziessel, S. Diring / Tetrahedron Letters 47 (2006) 4687–4692
4691
8.00
3.00
of this work in the form of an Allocation de Recherche
for S.D.
2
4a
Fc+/Fc
-2.00
-7.00
-12.00
References and notes
1. Kraft, A.; Grimsdale, A. C.; Holmes, A. B. Angew. Chem.
Int. Ed. 1998, 37, 402; Martin, R. E.; Diederich, F. Angew.
Chem. Int. Ed. 1999, 38, 1350; Segure, J. L.; Martin, N. J.
Mater. Chem. 2000, 10, 2403.
(a)
2000
1500
1000
500
0
-500
-1000
-1500
-2000
Potential/mV
2. Ziessel, R. Synthesis 1999, 1839.
3. Juris, A.; Balzani, V.; Barigelletti, F.; Campagna, S.; Beser,
P.; Von Zelewsky, A. Coord. Chem. Rev. 1988, 84, 85.
4. Chan, C. W.; Cheng, L. K.; Che, C. M. Coord. Chem. Rev.
1994, 132, 87; Paw, W.; Cummings, S. D.; Mansour, M.
A.; Connick, W. B.; Geiger, D. K.; Eisenberg, R. Coord.
Chem. Rev. 1998, 171, 125.
5. Hissler, M.; McGarrah, J. E.; Connick, W. B.; Geiger, D.
K.; Cummings, S. D.; Eisenberg, R. Coord. Chem. Rev.
2000, 208, 115.
6. Arena, G.; Monsu Scolaro, L.; Pasternack, R. F.; Romeo,
R. Inorg. Chem. 1995, 34, 2994.
7. Ratilla, E. M. A.; Brothers, H. M.; Kostic, N. M. J. Am.
Chem. Soc. 1987, 109, 4592.
15.00
10.00
5.00
6
9b
Fc+/Fc
0.00
-5.00
-10.00
(b)
2000
1500
1000
500
0
-500
-1000
-1500
-2000
Potential/mV
8. Michalec, J. F.; Bejune, S. A.; Cuttell, D. G.; Summerton,
G. C.; Gertenbach, J. A.; Field, J. S.; Haines, R. J.;
McMillin, D. R. Inorg. Chem. 2001, 40, 2193.
Figure 3. Cyclic voltammetry in dichloromethane containing 0.1 M
tetrabutylammonium hexafluorophosphate at rt, scan rate 200 mV sꢀ1
Ferrocene was used as internal reference +0.38 V versus SCE.
.
9. Yam, V. W. W.; Tang, R. P. L.; Wong, K. M. C.; Cheung,
K. K. Organometallics 2001, 20, 4476.
10. Yang, Q. Z.; Wu, L. Z.; Zhang, L. P.; Tung, C. H. Inorg.
Chem. 2002, 41, 5653.
11. Ha, F.; Kinayyigit, S.; Cable, J. R.; Castellano, F. N.
Inorg. Chem. 2005, 44, 471.
12. Liu, X.-J.; Feng, J.-K.; Meng, J.; Pan, Q.-J.; Ren, A.-M.;
Zhou, X.; Zhang, H.-X. Eur. J. Inorg. Chem. 2005, 1856.
13. Inouye, M.; Hyodo, Y.; Nakazumi, H. J. Org. Chem.
1999, 64, 2704.
14. Prepared by an adapted procedure from Thomas, K. R. J.;
Lin, J. T.; Lin, Y.-Y.; Tsai, C.; Sun, S.-S. Organometallics
2001, 20, 2262.
terpy-based reduction and the second reduction is tenta-
tively assigned to a metal-centred reduction whereas the
irreversible oxidation are likely assigned to fluorine and
pyrene based oxidation (Fig. 3a).20 In the bipyridine
complexes 6 and 9b, no such oxidation could be detected
within the given oxidation window but two reversible
reductions are also found at ꢀ0.99 (DEp = 60 mV) and
ꢀ1.50 V (DEp = 60 mV) in both complexes (Fig. 3b).
In summary, a series of mononuclear terpyridine–plati-
num(II) acetylide complexes bearing various appended
moieties (perylene, fluorene, pyrene, bipyridine, bipyri-
midine, terpyridine) and dinuclear complexes bridged
by a bipyridine, terpyridine or a back-to-back bis-ter-
pyridine ligand has been successfully synthesized using
a rational protocol. High solubility has been ensured
by the use of tert-butyl substituents on the terpy–Pt cen-
tre or by linear dodecyloxy chains grafted at the central
phenoxy moiety. The nature of the acetylide residues has
a strong influence on the absorption of the 3MLCT state
with a strong bathochromic shift observed for the elec-
tron-rich perylene module. This trend is confirmed by
increasing the number of pyrene nucleus. Preliminary
electrochemical studies showed two reversible redox
processes (ligand and Pt based) for the key complexes
2, 6 and 9b. Further work is directed towards the com-
plexation of the empty terpyridine and bipyridine sites
by luminescent transition metal salts in order to study
energy or electron transfer processes.
15. Harriman, A.; Hissler, M.; Khatyr, A.; Ziessel, R. Chem.
Commun. 1999, 735; Hissler, M.; Harriman, A.; Khatyr,
A.; Ziessel, R. Chem. Eur. J. 1999, 11, 3366.
16. Compound 7. The preparation began with the dissolution
of [(tBu3–terpy)PtCl](Cl) (0.163 g, 0.244 mmol) in a mix-
ture of DMF (3 mL) and triethylamine (1 mL), followed
by the addition of 4-ethynyl-2,20:60,600-terpyridine (0.063 g,
0.244 mmol). The solution was degassed vigorously by
bubbling argon through the solution. The addition of CuI
(0.001 g, 0.005 mmol) to the yellow solution resulted in the
instantaneous colour change to red. After stirring at rt for
one night, the deep-red solution is concentrated to roughly
1 mL and filtrated over Celite and dropped into an
aqueous solution (10 mL) containing NaBF4 (1.200 g).
The complex was recovered by filtration over paper,
washed with water (3 · 100 mL) and the red solid dried
under high vacuum. Purification was insured by column
chromatography using alumina as solid support and a
gradient of methanol (0–1%) in dichloromethane as
mobile phase. Ultimate recrystallization by slow evapora-
tion of dichloromethane from
a dichloromethane/
hexane solution afforded complex 7 (0.202 g, 88%). 1H
(200.1 MHz) NMR d 9.12 (d, 3J = 6.0 Hz, 2H), 8.97 (s,
2H), 8.96 (s, 2H), 8.89 (d, 3J = 8.0 Hz, 4H), 8.69 (dm,
3
3J = 4.8 Hz, 1H), 8.61 (d, J = 8.0 Hz, 1H), 8.47 (s, 2H),
Acknowledgements
7.87 (td, 3J = 8.0 Hz, 4J = 1.9 Hz, 1H), 7.60 (7 lines m,
2H), 7.34 (8 lines m, 1H), 1.65 (s, 9H), 1.52 ppm (s, 18H).
13C{1H} (100.6 MHz) d 169.3, 169.1, 168.3, 167.7, 162.5,
`
The Ministere de la Recherche et des Nouvelles Tech-
nologies is gratefully acknowledged for financial support