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

摘要

Precursors in the crystallisation of selected tetraalkylammonium and tetraalkylphosphonium chlorocuprates(I) and bromocuprates(I) from ethanol solution have been studied by means of electrospary ionisation mass spectrometry. The results are discussed in the context of previous work which indicates that large bulky unpositive cations can be used to tune the copper(I) coordination number in the halocuprate(I) anion with which the cation co-precipitates. Aggregates between quaternary ammonium or phosphonium cations and halide ions, with and without copper(I), have been observed. No evidence is found for the presence of the anions of higher nuclearity observed in the solids, the only halocuprate(I) ions observed in solution being CuX_2~- (X = Cl, Br).