TY - JOUR
T1 - Structure and photophysical properties of novel ruthenium(II) complexes containing 6-substituted bipyridines
AU - Hammarström, Leif
AU - Alsins, Jan
AU - Börje, Anna
AU - Norrby, Thomas
AU - Zhang, Lian
AU - Åkermark, Björn
PY - 1997/1/22
Y1 - 1997/1/22
N2 - 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.
AB - 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.
KW - Bipyridine
KW - Photophysical properties
KW - Ruthenium(II) complex
KW - Structure
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U2 - 10.1016/S1010-6030(96)04395-X
DO - 10.1016/S1010-6030(96)04395-X
M3 - Article
AN - SCOPUS:0031583045
VL - 102
SP - 139
EP - 150
JO - Journal of Photochemistry and Photobiology A: Chemistry
JF - Journal of Photochemistry and Photobiology A: Chemistry
SN - 1010-6030
IS - 2-3
ER -