Microwave, infrared, and Raman spectra and structure of germyl isothiocyanate

Abstract

The microwave spectra of H3 70Ge 14NCS, H3 72Ge 14NCS, H3 74Ge 14NCS, the corresponding -d3 compounds, H3 70Ge 15NCS, H3 72Ge 15NCS, H3 74Ge 15NCS, and H3 74Ge 14N 13CS have been recorded and analyzed from 12.4 to 40.0 GHz. The spectra are consistent with those for a symmetric top with a very low-frequency bending mode. Relative intensity measurements of the excited states indicate that the GeNC bending mode is about 50 cm−1. The rs distance for the Ge–N and N=C bonds were determined to be 1.817±0.015 Å and 1.144±0.015 Å, respectively. Other structural parameters were estimated which were consistent with the rotational constants of the 10 isotopic species. Infrared spectra of gaseous and solid GeH3NCS and GeD3NCS and Raman spectra of the corresponding liquids and solids were recorded from 30 to 3000 cm−1. The vibrational spectra of the gases are only consistent with a molecule with C3v symmetry. A complete vibrational analysis is presented and a normal coordinate calculation has been carried out.