PHOTOPHYSICAL AND ELECTROCHEMICAL CHARACTERIZATION OF PD(II) CYCLOMETALATED COMPLEXES WITH 2-ACETYLPYRIDINE-PHENYLHYDRAZONE

The absorption spectra, emission spectra, emission lifetimes and photo chemical and electrochemical behaviour of six monomeric cyclometallate d complexes [Pd(CNN)X]0,+ (where CNN is the C-deprotonated form of 2-a cetylpyridine-phenylhydrazone and X is I-, Cl-, 4-Mepy, PPh3, P(Oph)3, P(OMe)3) and two dimeric cyclometallated complexes [(CNN)Pd(XX)Pd(NNC )]2+ (where XX is 4,4'-bipyridine (4,4'-bpy) or bis(diphenylphosphino) methane (dppm)) were studied. The relatively intense absorption band e xhibited by the complexes at 450 nm and the luminescence emission obse rved at 298 and 77 K were assigned to intraligand (IL) transitions wit h remarkable charge transfer character (ILCT).