Organotin halides and their hydrolysed species studied in solution by positive and negative ion electrospray mass spectrometry

Hydrolysis products of the organotin compounds R(3)SnCl(R = Ph, Me or Bu(n)), Ph(3)SnBr and Ph(2)SnCl(2) have been investigated by electrospray mass spectrometry. Both positive and negative ion modes were employed to obtain information on the range of charged species produced in aqueous acetonitrile solution. The positive ion electrospray spectra of the triorganotin species yielded aggregates [(R(3)Sn)(n)(OH)(n-1)](+), alongside R(3)Sn(+) and solvated cations, including [R(3)Sn(NCCH3)(+)]. Addition of pyridine (py) to hydrolysed Ph(3)SnCl afforded predominantly [Ph(3)Sn(py)](+). In the negative ion spectra a number of species could be identified. Solutions of Ph(3)SnX (X = Cl or Br) yielded [Ph(3)SnX(2)](-), [Ph(3)SnX(OH)](-), [Ph(3)SnO](-) and [Ph(3)SnOSnPh(3)X](-), whilst those of Ph(2)SnCl(2) showed chiefly [Ph(2)SnCl(3)](-). Me(3)SnCl yielded [Me(3)SnCl(2)](-) accompanied by [Me(3)SnOSnMe(3) (OH)](-), whereas Bu(3)(n)SnCl gave [Bu(3)(n)SnCl(2)](-) and [Bu(3)(n)SnCl(OH)](-). Addition of Cl-, Br- and I- to a hydrolysed solution of Bu(3)(n)SnCl allows identification of all six mixed dihalostannate complexes [Bu(3)(n)SnXY](-) (X, Y = Cl, Br or I).