2,2 -Bipyridine, 4,4 -dicarboxy, ruthenium complexes

Other studies complemented the previous results and have also shown that a homochiral ion-pairing is favoured for Ru(DEAS-bpy)3 + complex (4.9) DEAS-bpy = 4,4 -bis(diethylamino-styryl)-[2,2 ]-bipyridine " and for the compounds [Ru(bpy)2(L-L)] [PFgli L-L = cmbpy = 4-carboxy-4 -methyl-2,2 -bipyridine (4.10) L-L = dcbpy = 4, 4 -dicarboxy-2,2 bipyridine (4.11). Interestingly, in the previous two examples the octahedral metal complexes have D3 symmetry as A-TRISPHAT (4.7) while in the last example complex 4.10 possesses a C symmetry while 4.11 displays a C2-symmetry (Figure 4.6). These results suggest that a homochiral association between A-TRISPHAT and the octahedral ruthenium complexes is not dependent on a prerequisite D3-symmetry of the metal complex. 

Scheme 3 shows the details of the synthetic strategy adopted for the preparation of heteroleptic cis- and trans-complexes. Reaction of dichloro(p-cymene)ruthenium(II) dimer in ethanol solution at reflux temperature with 4,4,-dicarboxy-2.2 -bipyridine (L) resulted the pure mononuclear complex [Ru(cymene)ClL]Cl. In this step, the coordination of substituted bipyridine ligand to the ruthenium center takes place with cleavage of the doubly chloride-bridged structure of the dimeric starting material. The presence of three pyridine proton environments in the NMR spectrum is consistent with the symmetry seen in the solid-state crystal structure (Figure 24). 

Kruger J, Plass R, Gratzel M, Matthieu H-J (2002) Improvement of the photovoltaic performance of solid-state dye-sensitized device by silver complexation of the sensitizer cis-bis(4,4-dicarboxy-2,2-bipyridine)-bis(isothiocyanato)ruthenium(II). Appl Phys Lett 81 367... 

The two-stranded p-sheet models (77,78) used a novel ruthenium polypyri-dyl complex, Ru(bpy)2L, to bring two valinyl peptide chains in close proximity to one another (Fig. 13), where L = 3,5-dicarboxy-2,2 -bipyridine [88]. In these studies, 2-D NMR was again used to show that the individual peptide chains of 78 possessed the requisite properties of a P strand. Evidence for the assignment of significant P-sheet character to 78 was obtained from the temperature coefficients of the chemical shifts of the amide protons, which indicated that the C-terminal amide of the peptide chain attached to the C-3 position of L was involved in an intramolecular hydrogen bond (Fig. 13). In contrast, the bis(monovaline) peptide, 77, was too small to form any type of organized structure. 

O4N2C12H8, Bipyridine, 4,4 -dicarboxy-2,2 -, ruthenium(II) complexes, 33 185 O4N2C20H16, Amine, N,N -bis(salicylidene)-4,5-dihydroxyphenylenedi-, 33 116 O4N2C36H46 (C2H5)20, Amine, N,N -... 

Rensmo H, Sodergren S, Patthey L, Westermark K, Vayssieres L, Kohle O, Briihwiler PA, Hagfeldt A, Siegbahn H (1997) The electrraiic structure of the c(s-bis(4,4 -dicarboxy-2, 2 -bipyridine)-bis(isothiocyanato)ruthenium(n) complex and its ligand 2,2 -bipyridyl-4, 4 -dicarboxylic acid studied with electron spectroscopy. Chem Phys Lett 274(l-3) 51-57... 

Kruger J., Plass R, Grdtzel M. Improvement of the photovoltaique performance of solide-state dye-sensitized device by silver complexation of the sensitizer < M-bis(4,4 -dicarboxy-2,2 -bipyridine)-bis(isothiocyanato) ruthenium(ll). Appl. Phys. Lett. 2002 81(2) 367-369 Kubo W., Kitamura T., Hanabusa K., Wada Y., Yanagida S. Chem. Commun. 2002 374-375 Meng Q.B., Takahashi K., Zhang X.-T., Sutanto L, Rao T.N., Sato O., Fujishima A., Watanabe H., Nakamori T., Uragami M. Fabrication of an efficient solid-state dye-sensitized solar cell. Langmuir 2003 19(9) 3572-3574... 

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