Bis(triphenylphosphine)copper(I) derivatives of substituted arachno nine-vertex borane anions, Cu(PPh3)2(B9H13X)(X = H, NCS, NCSe, NCBPh3, NCBH3, or NCBH2NCBH3)

Abstract

A series of metallaboranes, Cu(PPh₃)₂(B₉H₁₃X)(1)–(6), derived from substituted derivatives of the tetradecahydrononaborate(1–) ions, [B₉H₁₃X]^–, in which X is respectively H, NCS, NCSe, NCBPh₃, NCBH₃, or NCBH₂NCBH₃, have been prepared by treating salts of the anions with bis(triphenylphosphine)copper(I) tetrahydroborate. The new bis(triphenylphosphine)copper(I) nonaboranes (1)–(4) are shown by their ¹¹B, ¹H, and ³¹P n.m.r. spectra to be fluxional in solution, down to –50 °C. All the neutral complexes are undissociated in dichloromethane but dissociate in acetonitrile solutions. In complexes (1)–(4), the metal and borane interact through hydrogen bridges on the B₉ cage. In complexes (5) and (6) the interaction occurs through the BH₃ moiety.