Synthesis, Characterization, and Sensitizing Properties of Heteroleptic RuII Complexes Based on 2,6-Bis(1-pyrazolyl)pyr­idine and 2,2′-Bipyridine-4,4′-dicarboxylic Acid Ligands

✍ Scribed by Athanassios I. Philippopoulos; Aris Terzis; Catherine P. Raptopoulou; Vincent J. Catalano; Polycarpos Falaras

• Publisher: John Wiley and Sons
• Year: 2007
• Tongue: English
• Weight: 348 KB
• Volume: 2007
• Category: Article
• ISSN: 1434-1948
• DOI: 10.1002/ejic.200700287

✦ Synopsis

Abstract

Starting from the Ru(bpp)Cl~3~ precursor (1), a family of novel heteroleptic Ru^II^ complexes of the general formulae [Ru(bpp)(dcbpyH)(X)] [X = Cl^–^ (2a), NCS^–^, (3)] and Na[Ru(bpp)(dcbpy)(CN)] (4) with the ligands 2,6‐bis(1‐pyrazolyl)pyridine (bpp) and 2,2′‐bipyridine‐4,4′‐dicarboxylic acid (dcbpyH~2~) has been synthesized, spectroscopically characterized, and attached to nanocrystalline TiO~2~ electrodes to be tested as solar cell sensitizers. Addition of HCl to (2a) led to the corresponding cationic derivative [Ru(bpp)(dcbpyH~2~)Cl]Cl (2b). All complexes were characterized by FT‐IR, FT‐Raman, UV/Vis, ^1^H NMR spectroscopy, elemental analysis, and mass spectrometry. Complex 4 and the previously reported Ru(bdmpp)(dcbpyH~2~)Cl (5) [bdmpp is 2,6‐bis(3,5‐dimethyl‐1‐pyrazolyl)pyridine] were characterized by single‐crystal X‐ray diffraction. The photo‐electochemical properties of the dyes 2–4 were investigated and the efficiency of the corresponding dye‐sensitized solar cells was compared to the sensitizing performance of the cis‐Ru(dcbpyH)~2~(NCS)~2~~2~ (N719) dye.(© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2007)