Manganese(i) poly(mercaptoimidazolyl)borate complexes: spectroscopic and structural characterization of Mn⋯H–B interactions in solution and in the solid state

Abstract

The manganese(I) tricarbonyl complexes (Bm^R)Mn(CO)₃ (R = Me, Bz, Bu^t, p-Tol) and (PhBm^Me)Mn(CO)₃, the first bis(mercaptoimidazolyl)borate derivatives for this metal, have been readily prepared and fully characterized. In particular, the presence of three-center–two-electron Mn⋯H–B interactions in these species, both in solution and in the solid state, has been investigated using a combination of IR and NMR spectroscopies and, in the case of the methyl-, tert-butyl- and para-tolyl-substituted derivatives, by X-ray crystallography. To complement these synthetic and structural studies, the tris(mercaptoimidazolyl)borate complexes (Tm^Me)Mn(CO)₃ (R = Me, Bz, Bu^t, p-Tol) and (PhTm^Me)Mn(CO)₃, as well as the related pyrazolylbis(mercaptoimidazolyl)borate (pzBm^Me)Mn(CO)₃, have also been synthesized and characterized by a combination of analytical and spectroscopic techniques.