SYNTHESIS, PHOTOPHYSICAL, PHOTOCHEMICAL AND ELECTROCHEMICAL PROPERTIES OF RHENIUM(I) DIIMINE COMPLEXES WITH PHOTOISOMERIZABLE PYRIDYL-AZO, PYRIDYL-ETHENYL OR PYRIDYL-ETHYL LIGANDS

A series of rhenium(I) diimine complexes with pyridyl-azo, -ethenyl or -ethyl type ligands, [Re(CO)(3)(N-N)L]ClO4 and [{Re(CO)(3)(N-N)}(2)L' ][ClO4](2) {N-N = 2,2'-bipyridine (bpy), 1,10-phenanthroline (phen); L = 4-phenylazopyridine (PHAZO), 4-styrylpyridine (STYPY), [2-(4-pyridy l)ethyl]benzene (PEB), 4-(4-nitrostyryl)pyridine (NSP); L' = 4,4'-azop yridine (AZO), 1,4-bis[2-(4-pyridyl)ethenyl]benzene (BPENB), 1,4-bis[2 -(4-pyridyl)ethyl]benzene (BPEB)} have been synthesized and their phot ophysical properties studied. The quantum yields for the photoinduced isomerization of the complexes [Re(CO)(3)(bpy)(NSP)](+) and [Re(CO)(3) (phen)(NSP)](+) have been determined.