Synthetic, spectral and structural aspects of some Rh(III) pentamethylcyclopentadiene complexes containing N ' N '-donor bridging ligands

Reactions of the chloro-bridged dimeric rhodium complex [{(eta(5)-C5Me5)Rh(mu-Cl)Cl}(2)] with the N ,N'-donor bridging ligands pyridine-2-carbaldehyde azine (paa), p-phenylene-bis(picoline)aldamine (pbp) or p-biphenylene-bis(picoline)aldamine (bbp) in 1:1 molar ratio in methanol led in the formation of cationic binuclear complexes [(eta(5)-C5Me5)ClRh(mu-L)RhCl(eta(5)-C5Me5)](2+) (L = paa, pbp or bbp) in high yield. It was further observed that reactions of the chloro-bridged dimeric rhodium complex [{(eta(5)-C5ME5)Rh(mu- Cl)Cl}(2)], with an excess of the above mentioned ligands also, resulted in binuclear complexes. The reaction products have been characterized by microanalyses and spectroscopic studies (IR, H-1-, C-13-NMR, ESMS/FAB mass and electronic spectra). Molecular structure of the representative binuclear complex [(eta(5)-C5Me5)ClRh(mu-paa)RhCl(eta(5)-C5Me5)](BF4)(2) has been confirmed by single crystal X-ray analysis. Crystal data: monoclinic, P2(1)/n, a = 10.2050(7), b = 15.4470(7), c = 24.959(2) Angstrom, beta = 97.904(6)degrees, V = 3897.1(5) Angstrom(3), Z = 4, R = 0.0609. (C) 2002