THE COORDINATION CHEMISTRY OF SOME POLYAZINE DERIVATIVES

Abstract

Transition metal complexes of azaarene derivatives such as quinoxalines are important models for bioinoranic systems. Also, the interest in these systems is retained to the facile electrochemical properties, magnetic coupling interactions, catalytic processes and their application as photosensitizers. The ligand 2,3-bis(2•-pyridyl)quinoxaline (dpq) was chosen to investigate its reactions with either Ru 3(C0) 12, RuC13 or RhC13 • Reaction of (dpq) with Ru 3(C0) 12 in benzene gave the dinuclear complex [Ru(C0)3h(dpq) as a predominant product. In presence of either 2,2'-dipyridine (dpy) or pyridine (py), the mononuclear complexes [Ru(CO)J(dpq)] and [Ru(C0)2(dpq)(py)] were isolated. Reactions ofRuC13 with dpq under reduced pressures in benzene/ethanol mixed solvent yielded the bis derivative [Ru(dpq)2 CI2 ]CI. Three complexes, [Rh2(dpq)2CI6], [Rh(dpq)2 • CI2]CI and [Rh(dpq)(py)C13], were isolated from the reactions of RhCI3 with dpq. The type of product was dependent on reaction constituents and conditions. Spectroscopic studies of all complexes were consistent with the proposed structures.