Highly efficient polypyridyl-ruthenium(II) photosensitizers with chelatingoxygen donor ligands: beta-diketonato-bis(dicarboxybipyridine)ruthenium

Citation
Y. Takahashi et al., Highly efficient polypyridyl-ruthenium(II) photosensitizers with chelatingoxygen donor ligands: beta-diketonato-bis(dicarboxybipyridine)ruthenium, INORG CHIM, 310(2), 2000, pp. 169-174
Citations number
25
Categorie Soggetti
Inorganic & Nuclear Chemistry
Journal title
INORGANICA CHIMICA ACTA
ISSN journal
00201693 → ACNP
Volume
310
Issue
2
Year of publication
2000
Pages
169 - 174
Database
ISI
SICI code
0020-1693(200012)310:2<169:HEPPWC>2.0.ZU;2-9
Abstract
A series of mono-cationic polypyridyl-ruthenium complexes with strongly ele ctron donating beta -diketonate ligands {(dcbp)(2)Ru(L)}Cl, where dcbp = 4, 4'-dicarboxy-2,2'-bipyridine; L = acetylacetonate (1), 3-methyl-2,4-pentane dionate (2), 1,3-diphenyl-1,3-propanedionate (3), have been synthesized as molecular photosensitizers for a nanocrystalline TiO2 electrode. In alkalin e methanol solution, these complexes exhibit intense visible light absorpti on with low energy MLCT maxima above 517 nm which accompany a significantly enhanced band tail, improving red light absorptivity beyond 600 nm. The ph otoelectrochemical properties of these three diketonate complexes on a TiO2 semiconductor have been compared to cis-dithiocyanate complex, (dcbp)(2)Ru (NCS)(2), which is one of the most efficient sensitizers reported to date. The diketonate complexes show quite high performances in photoelectrochemic al cells containing I-/I-3(-) electrolyte. The overall solar light-to-elect rical energy conversion efficiencies are in the range of 6.0-3.9% while the dithiocyanate complex yields 5.7% efficiency in our experiments. (C) 2000 Elsevier Science B.V. All rights reserved.