Mono- and dinuclear carbonyl complexes of (1,4,7-trimethyl-1,4,7-triazacyclononane)rhodium(I): Facile migration of a C(O)OMe ligand at a dinuclear Rh(mu-CO)(2)Rh core
de Bruin B, Donners JJJM, de Gelder R, Smits JMM, Gal AW
EUROPEAN JOURNAL OF INORGANIC CHEMISTRY (3): 401-406 MAR 1998

Abstract:
The reaction of 1,4,7-trimethyl-1,4,7-triazacyclononane (Cn*) with [{(CO)(2)Rh(mu-Cl)}(2)] in methanol at 0 degrees C, followed by the addition of NH4PF6, results in the formation of the mononuclear carbonyl complex [Cn*Rh(mu-CO)(2)]PF6 ([1]PF6), the dinuclear carbonyl complex [Cn*Rh(mu-CO)(3)RhCn*] (PF6)(2) I[2](PF6)(2)) and the dinuclear methoxycarbonyl complex [Cn* Rh(C(O)OMe) (mu-CO)(2)RhCn*]PF6 ([3]PF6). The reaction of[2](PF6)(2) with NaOMe results in formation of [3]PF6 by the attack of the methoxide at a bridging carbonyl. Treatment of [3]PF6 with NH4PF6 regenerates [2](PF6)(2), thus showing that the methoxylation of [2](PF6)(2) is reversible. The structures of [1]PF6, [2](PF6)(2) and [3]PF6 have been determined by single-crystal X-ray diffraction. For [3]PF6 an unprecendented facile, reversible, migration of the C(O)OMe ligand between the two rhodium centres of the Rh(mu-CO)(2)Rh core is observed.