Abstract
A series of four binuclear rhenium (I) complexes of the general form [Re(CO)3Cl]2BL, where BL is a polypyridyl bridging ligand, have been studied using ultrafast time-resolved UV/visible (TRVIS) and infrared (TRIR) spectroscopies. Visible excitation produces a metal-to-ligand charge-transfer (MLCT) excited state. Kinetic measurements show that the lifetime of this MLCT state varies between 100 and 1900 ps, depending on the structure of the bridging ligand. TRIR difference spectra show that each complex forms a similar MLCT state which has mixed valence character.