[{ReH₂(PMePh₂)₂}₂(μ-H)₃]^-:  The First Member of a New Class of Anionic Polyhydride Dimers [Re₂H₇L₄]^-

Abstract

[K(Q)][{ReH2(PMePh2)2}2(μ-H)3] is prepared by treatment of {ReH2(PMePh2)2}2(μ-H)4 with potassium hydride and a crown ether (Q = 18-crown-6 or 1,10-diaza-18-crown-6). The [K(1,10 diaza-18-crown-6)]+ salt contains NH...HRe protonic−hydridic bonds and has been characterized by 31P NMR, variable temperature 1H NMR, IR, and X-ray crystallography. The pKαTHF = 33 of {ReH2(PMePh2)2}2(μ-H)4 was determined on the basis of its reaction with [K(2,2,2-crypt)][PO(OEt)2NPh].