Synthesis and characterization of Cp ∗Rh (III) and Ir (III) polypyridyl complexes: : fluxional behaviour of Rh (III) complexes and molecular structure of [Cp∗Rh (Ph-terpy)Cl]BF4 complex (Cp∗=η 5− (C5Me5))

Abstract

Reaction of [Cp ∗M( μ-Cl)Cl] 2 (Cp ∗= η 5- (C 5Me 5), MRh, Ir) with 4′-phenyl-2,2′: 6′, 2″ terpyridine (Ph-terpy), L 1 and 1,4-bis (2,2′: 6′, 2″-terpyridin-4′-yl)benzene (diterpy), L 2 results in the formation of cationic complexes by the cleavage of halide bridge. These complexes, [Cp ∗RhL 1Cl]BF 4, (1), [ (Cp ∗RhCl) 2L 2] (BF 4) 2, (2), [Cp ∗IrL 1Cl]BF 4, (3) and [ (Cp ∗IrCl) 2L 2] (BF 4) 2, (4) are characterised by various spectral methods. Ph-terpy coordinates the metal ion in a bidentate fashion to form mononuclear complexes while diterpy bridges two metal ions to form dinuclear complexes. Complex (1) is crystallographically characterised. In solution Rh (III) complexes show fluxional behavior.