Spectra and structure of organophosphorus compounds. XXIV. Microwave, infrared, and Raman spectra, conformational stability, and vibrational assignment for chloromethylphosphonic difluoride

The microwave spectrum of chloromethylphosphonic difluoride, ClCH2P(O)F2, has been investigated in the region from 26.5 to 39 GHz. The a‐type R branch transitions have been assigned for both the 35Cl and 37Cl isotopic species for the trans conformer on the basis of the rigid rotor model. For the ground vibrational state the rotational constants for the 35Cl isotope were found to be A = 4392.4±2.3, B=1543.36±0.01, and C=1512.30±0.01 MHz and for the 37Cl isotope: A=4395.3±2.7, B=1502.04±0.01, and C=1472.54±0.01 MHz. With reasonably assumed structural parameters for the C–H and P=0 distances as well as the HCH angle, a diagnostic least‐squares adjustment was utilized to obtain the other six structural parameters. The dipole moment components were determined from the Stark effect to be ‖μa‖ =2.28±0.05, ‖μb‖ =0.75±0.02, and ‖μt‖ =2.40±0.02 D. The infrared (3500–40 cm−1) and Raman (3500–20 cm−1) spectra of the gas and solid have been recorded. Additionally, the Raman spectrum of the liquid has been recorded and...