Solvation of mercury(II) halides and alkylmercury(II) halides by liquid ammonia: a Raman spectroscopic study

Abstract

Raman spectra are reported for HgX₂(X = Cl, Br, or I), [HgEt(Cl)], [HgBr(Me)], and [HgMe(I)] dissolved in liquid ammonia and liquid ND₃. The spectra have been recorded at ambient temperatures and the results obtained for all six compounds are quite different to those reported previously for solutions in weakly co-ordinating non-aqueous solvents. The spectra for the chloro- and bromo-compounds have been satisfactorily interpreted in terms of [Hg(NH₃)₄]²⁺ and [HgR(NH₃)₃]⁺ cations, but the iodo-compounds generate different species. Mercury(II) iodide exists as [Hgl(NH₃)₃][l(solvated)], while the following equilibrium is shown to be present for [HgMe(I)] : [HgMe(I)][graphics omitted] [HgMe(I)(NH3)₂]⇌[HgMe(NH3)₃][I(solvated)].