INFRARED AND RAMAN SPECTRA, CONFORMATIONAL STABILITY, AND VIBRATIONAL ASSIGNMENT OF CYCLOBUTYLGERMANE

Author Institution: Department of Chemistry, University of South Carolina; Abteilung f\""{u}r Physikalische Chemie, Universit\""{a}t UlmThe infrared $(3500 to 50 cm^{-1})$ and Raman $(3500 to 20 cm^{-1})$ spectra of gaseous and solid cyclobutylgermane, $c-C_{4}H_{7}GeH_{3}$, have been recorded. Additionally, the Raman spectrum of the liquid has been recorded and qualitative depolarization values have been obtained. From a comparison of the spectra of the fluid phases with that of the solid, it is clear that two stable conformers exist in the fluid phases at ambient temperature. It has been determined that the equatorial conformer is the predominant form at ambient temperature in the gas phase and, from a temperature study of the Raman spectrum in this phase, the enthalpy difference between the equatorial and axial conformers has been determined. Similar studies of the Raman spectrum of the liquid phase have also been carried out, again with the equatorial conformer being thermodynamically preferred and the only conformer present in the solid state. A series of Q-branches have been observed in the low frequency Raman spectrum of the gas and have been assigned to transitions arising from the ring-puckering mode of both conformers. These data have been used to calculate the potential function governing the ring inversion in this molecule