Selective on-line deuteration in gas chromatography - mass spectrometry for the investigation of dissociative ionization of silicon-containing compounds

A method for specific gas-phase deuteration of unsaturated silicon-containing compounds over pre-heterogenized Wilkinson's catalyst (a solution of (Ph₃P)₃RhCl in Carbowax 20M coated on Chromaton) in the reaction column connected to the mass spectrometer is described. This method was employed to study the dissociative ionization of the corresponding saturated analogues. With the aid of the mass spectra of the dideutero derivatives thus obtained, the main electron-impact-induced reactions of 1,1-dimethyl-1-silacyclopentane, 1,1,2,2-tetramethyl-1,2-disilacyclohexane, 1-methyl-1-ethyl-1-silacyclobutane and ethyl triethoxysilane were elucidated.