On tuning the copper(I) coordination number in halocuprate(I) anions: new insights into cation control

Precursors in the crystallisation of selected tetraalkylammonium and tetraa lkylphosphonium chlorocuprates(I) and bromocuprates(I) from ethanol solutio n have been studied by means of electrospray ionisation mass spectrometry. The results are discussed in the context of previous work which indicates t hat large bulky unipositive cations can be used to tune the copper(I) coord ination number in the halocuprate(I) anion with which the cation co-precipi tates, Aggregates between quaternary ammonium or phosphonium cations and ha lide ions, with and without copper(I), have been observed. No evidence is f ound for the presence of the anions of higher nuclearity observed in the so lids, the only halocuprate(I) ions observed in solution being CuX2- (X = Cl , Br). (C) 1999 Elsevier Science S.A. All rights reserved.