QUENCHING BY UNSATURATED FERROCENE DERIVATIVES OF THE LUMINESCENCE OFRU(BPY)(3)(2+)

A series of unsaturated ferrocene derivatives with the formula Fc-CH=C H-X (X = CHO, CN, COCH3, COOCH3, 4-py; Fc, ferrocene) were synthesized . They were found to exhibit reversible one-electron oxidation and two one-electron reduction steps. Quenching of the excited state of Ru(bp y)(3)(2+) (bpy, 2,2'-bipyridine) by the ferrocene derivatives was also studied. Quenching occurs mainly via electron transfer on the ferroce nyl group in acetonitrile. The results are confirmed by molecular orbi tal calculations using the CNDO method. A quenching mechanism is sugge sted. The bimolecular quenching rate constants were obtained from the Stern-Volmer equation. Linear relationships are obtained for a plot of log K-q vs. -Delta G of electron transfer.