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

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 -... 

In another research, fullerene (Ceo) was attached to N3 dye (cis-bis(4,4-dicarboxy-2,2-bipyridine)dithiocyanato ruthenium(II)) via diaminohydrocarbon linkers (L) with different carbon chain lengths. The results of this study indicated that in the case of the linker 1,6-diaminohexane, the current density, applied potential and conversion efficiency of the pertaining cell were 11.75 mA/cm, 0.70 V and 4.5%, respectively, as compared with the values of 10.55 mA/cm, 0.68V and 4.0%, respectively, for a DSSC with an ordinary N3 dye [198]. 

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). 

As described in Section II.A.3, dx-bis(4,4 -dicarboxy-2,2 -bipyridine)dithiocya-nato ruthenium(II) (N3 dye) and trithiocyanato 4,4 4"-tricarboxy-2,2 6, 2"-terpyr-idine ruthenium(II) (black dye) exhibit quite good performance therefore, the systems using these two Ru dyes have been intensively investigated. However, other Ru dye photosensitizers have also been synthesized and characterized, and their performances as photosensitizers in DSSCs have been reported by many researchers [98-116]. Several kinds of electron withdrawing ligand for Ru dye photosensitizers are shown in Fig. 13. Figure 14 shows the structures of newly synthesized Ru dye photosensitizers and their absorption properties. The axis shows the molar absorption coefficient, e (i.e., absorption coefficient per M unit M 1 cm-1). 

The X-ray and UV-photoemission spectroscopy study has revealed that ruthenium (II) phthalocyanine 20 has similar HOMO and LUMO energy with that of cis-bis(4,4-dicarboxy-2,2-bipyridine)-bis-(isothiocyanato)-ruthenium(II), [Ru(dcbpy)2 (NCS)2], the most efficient sensitizer so far. The oxidation potentials for both... 

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... 

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. 

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. 

N4C32H22, Porphyrin, 5,15-diphenyl-, 33 60 N4CI2O8RUC24H16, Ruthenium(ll), dichloro-bis(4,4 -dicarboxy-2,2 -bipyridine)-, cis-, 33 185... 

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... 

---