Vibrational spectra and structure of organophosphorous compounds. 20—infrared and raman spectra, vibrational assignment and normal coordinate calculations of methyldifluorophosphine

✍ Scribed by J. R. Durig; A. E. Stanley; M. R. Jalilian

• Publisher: John Wiley and Sons
• Year: 1981
• Tongue: English
• Weight: 764 KB
• Volume: 10
• Category: Article
• ISSN: 0377-0486
• DOI: 10.1002/jrs.1250100109

✦ Synopsis

Abstract

The Raman spectra of gaseous, liquid and solid CH~3~PF~2~ and the infrared spectra of the gas and solid have been recorded (3200–20 cm^−1^). The assignment of the 15 fundamentals is given and discussed and is based on the gas phase infrared band contours, depolarization values and group frequencies. A normal coordinate calculation was carried out by utilizing a modified valence force field to calculate the frequencies and the potential energy distributions. Extensive mixing was found between the PF~2~ stretching and CH~3~ rocking modes. The methyl torsion was observed at 192 cm^−1^ in the far‐infrared spectrum of the gas and from this frequency a three‐fold barrier to internal rotation of 1.74 kcal mol^−1^ was calculated. This value is compared to similar quantities in several other group VA compounds and the observed trends are consistent with those for the corresponding group IVA compounds.