Reactions of Sodium Tetrahydroborate and Cyanotrihydroborate With Divalent Co, Ni, Cu, Pd, and Pt Chlorides In the Presence of Tertiary Phosphines

Abstract

The reactions of divalent Co, Ni, Cu, Pd, and Pt chlorides with NaBH4 and NaBH3CN in the presence of tertiary phosphines under inert atmosphere conditions have been examined. The nature of the product varies enormously depending upon reaction conditions, and compounds obtained include complexes involving coordinated BH4− and BH3CN− of the type MLn, MBLn, and MHBLn, (L = phosphine, B = BH4− or BH3CN−, n = 2, 3, or 4). The first univalent nickel and cobalt BH4 complexes are reported. Platinum abstracts the CN group from BH3CN− to form the species PtH(CN)L2. Infrared spectral data are reported and appear to indicate two types of bonding (M—N and M—H) between BH3CN− and metals. Some electronic reflectance spectra and magnetic properties are also reported, including those of Co(I) and Ni(I) species. Attempts are made to rationalize the data in terms of a suggested mechanism for the reduction of metal halides by NaBH4.