Organo-rhodium(I) complexes containing mono and bidentate N-heterocycles

Complexes of the type [Rh(diolefin)(μ-X)]₂ [X = Cl or Br; diolefin = cod (cycloocta-1,5-diene) or nbd (norbornadiene)] undergo dihalobridge cleavage with 2-substituted benzimidazoles to produce mononuclear complexes, RhX(diolefin)(R-BzlH) (R = α-Py or Ph), and N-heterocycle bridged dimers, [RhX(diolefin)]₂(μ-N–N) (N–N = β-PyBzlH or γ-PyBzlH). Facile replacement ofone or both diolefins by CO occurs in the products to yield the corresponding di/tetracarbonyl complexes. Probable structures have been proposed for the complexes on the basis of physical, i.r., far-i.r. and ¹H- and ¹³C-n.m.r. spectral techniques and FAB-MS. This revised version was published online in June 2006 with corrections to the Cover Date.