Reactivity of [M(eta(4)-P(2)C(2)tBu(2))] (M = Ge, Sn) with tert-butylphosphaethyne, P=CtBu: Synthesis, structural characterisation and computational studies of the novel zwitterionic organophosphorus cage compounds [MP(4)C(4)tBu(4)] (M = Ge, Sn)

摘要

Treatment of [M(eta(4)-P(2)C(2)tBU(2))] with the phosphaalkyne P CtBu leads to the formation of the unusual zwitterionic cage compounds (M(P(4)C(4)tBu(4))] (M = Ge, Sn) which have been fully characterised in solution by multinuclear NMR spectroscopy and the solid-state structure of [GeP(4)C(4)tBu(4)] has been elucidated by a single-crystal X-ray diffraction study. DFT calculations support the zwitterionic formulation and suggest the likely reaction pathway. Whilst [GeP(4)C(4)tBU(4)] exhibits considerable stability, [SnP(4)C(4)tBU(4)] shows gradual decomposition in solution within a matter of hours. (C) Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2008)