Vibrational spectra, vibrational analysis, and shapes of some 1 : 1 and 1 : 2 addition compounds of group IV tetrahalides with trimethylamine and trimethylphosphine

Abstract

The vibrational spectra of SiF₄,Me₃N; SiF₄,2Me₃N; SiCl₄,2Me₃P; SiBr₄,2Me₃P; GeCl₄,2Me₃P; SnCl₄,2Me₃P; SiF₄,Me₃P; SiF₄,2Me₃P; SiCl₄,Me₃N; and GeCl₄,Me₃N are reported (including deuteriation studies in several cases). The preparation and characterisation of the compounds GeCl₄,2Me₃P and SnCl₄,2Me₃P is reported. For the 1 : 2 adducts a trans-octahedral shape is strongly suggested by the vibrational data. The vibrational spectra of GeCl₄,Me₃N (including both solution and oriented single crystal Raman measurements) support a C_3v model, as does the data on SiCl₄,Me₃N. In the case of the 1 : 1 adducts of silicon tetrafluoride a C_3v model is acceptable, but not proved.