753-98-0Relevant academic research and scientific papers
Conformational stability of CH3CH2P(Z)F2 (Z = O,S) from temperature dependent FT-IR spectra of rare gas solutions and r(o) structural parameters
Durig,Robb II,Xiao,Gounev
, p. 131 - 152 (2000)
Variable temperature (from -55 to -150°C) studies of the infrared spectra (3500-400 cm-1) of ethylphosphonic difluoride, CH3CH2P(O)F2 and ethylphosphonothioic difluoride, CH3CH2P(S)F2 dissolved in liquid xenon or krypton have been recorded. From these data, the enthalpy differences have been determined to be 76 ± 9 cm-1 (0.91 ± 0.11 kJ/mol), for CH3CH2P(O)F2 with the trans conformer the more stable rotamer and 53 ± 7 cm-1 (0.63 ± 0.08 kJ/mol) for CH3CH2P(S)F2 but with the gauche conformer the more stable form. Complete vibrational assignments are presented for both molecules, which are consistent with the predicted frequencies obtained from the ab initio MP2/6-31G(d) calculations. The optimized geometries, conformational stabilities, harmonic force fields, infrared intensities, Raman activities, and depolarization ratios have been obtained from RHF/6-31G(d) and/or MP2/6-31G(d) ab initio calculations. These quantities are compared to the corresponding experimental quantities when appropriate as well as with some corresponding results for some similar molecules. The r(o) adjusted structural parameters have been obtained for both molecules from a combination of the microwave rotational constants and ab initio predicted parameters. The corresponding r(o) structural parameters have been obtained for some similar molecules for comparison.
