A series of novel tris(bpy)ruthenium(II)-type complexes (where bpy = 2,2′-bipyridine) Ru(bpy)2(6-carboxylato-2,2′-bpy) hexafluorophosphate, Ru(bpy)2((2,2′-bpy-6-yl)-acetic acid) dihexafluorophosphate, Ru(bpy)2(6-methoxycarbonyl-2,2′-bpy) dihexafluorophosphate, and Ru(bpy)2(6-methyl-2,2′-bpy) dihexafluorophosphate were synthesised, and characterised by NMR spectroscopy, cyclic voltammetry, absorption and emission spectroscopy. The dominating effect of the substituent on the emission properties was an increased radiationless deactivation via metal-centered states, leading to a very short lifetime at 298 K. The degree of modification of the photophysical properties compared to those of Ru(bpy)2+ 3 followed the degree of geometric distortion introduced by the substituted ligand as suggested by NMR spectroscopy. In Ru(bpy)2(6-carboxylato-2,2′-bpy) hexafluorophosphate, an abnormal temperature dependence of the rate of radiative decay was observed. This may probably be explained by participation of metal-to-ligand charge transfer (MLCT) states originating from different, non-equivalent ligands.
|Number of pages||12|
|Journal||Journal of Photochemistry and Photobiology A: Chemistry|
|Publication status||Published - Jan 22 1997|
- Photophysical properties
- Ruthenium(II) complex
ASJC Scopus subject areas
- Physical and Theoretical Chemistry