Rotational Spectrum, Molecular Constants, Dipole Moment, and Internal Rotation in Vinylphosphine

Article abstract of DOI:10.1006/jmsp.1994.1186

The rotational spectra of both CH2=CHPH2 and CH2=CHPD2 have been measured from 8 to 320 GHz.Rotational constants, centrifugal distortion constants, and dipole moment components heve been determined.Only the gauche form (dihedral angle of 118.6 deg between the lone pair of phosphorus and the C=C bond) was found.With assumed bond lengths and bond angles for the vinyl part, the remaining structural parameters have been derived by fitting them to the six rotational constants.Structural results are compared with those of other phosphine derivatives.Internal rotation between two equivalent gauche configurations of CH2=CHPH2 causes splittings of μ_c transitions, which have been analyzed using the phenomenological group-theoretical Hamiltonian.