A series of rhenium(I) 2,2'-bipyridyl complexes [fac-(4,4'-di-COOEt-bpy)Re(CO)₃(Xpy)PF₆] (bpy=2,2'-bipyridine; py=pyridine; X=3-methyl, 3-hydroxy, 3-amino, H) were synthesized. Their electrochemical properties, ground state electronic spectra and emission spectra were studied in acetonitrile. As the X group became moreelectron donating from H to 3-methyl, 3-hydroxy or 3-amino, the Re(II/I) oxidation potentials declined, the MLCT absorption maximum of the complex was changed little, the emission maximum blue-shifted, and the emission intensity and the fluorescence lifetime were decreased.

Key words: rhenium(I) bipyridyl complex, photosensitive dye, nanocrystalline photovoltaic cell