SYNTHESIS, SPECTROSCOPIC, PHOTOPHYSICAL AND ELECTROCHEMICAL PROPERTIES OF CYANO-BRIDGED COPPER(I)-RUTHENIUM(II) COMPLEXES

Complexes of the formula [(N-N)Cu(AsPh3)CN] (N-N =2,2'-bipyridine, 1,1 0-phenanthroline) have been synthesized. Ru(bpy)(2)Cl-2. 2H(2)O and [( eta(5)-cp)Ru(PPh3)(2)Cl] react with [(N-N)Cu(AsPh3)CN] to give cyano-b ridged compounds. IR spectral studies in the low frequency region (700 -50 cm(-1)) and 4000-400cm(-1) region reveal cyano bridging in the com plexes. Luminescence measurements suggest oxidation of metal centres ( Cu-I-Cu-II and Ru-II-Ru-III) on excitation at a charge transfer band. This has been substantiated with electrochemical studies of complexes which exhibit quasi-reversible reductions viz. Ru-III/Ru-II and Cu-II/ Cu-I. The deposition of metallic copper is also observed at a potentia l of -1.55 V. Based on these data, a mechanism for photo-redox reactio n of complexes has been presented. The properties of these bimetallic complexes are compared with those of parent complexes. (C) 1998 Elsevi er Science Ltd. All rights reserved. (C) 1998 Elsevier Science Ltd. Al l rights reserved.