The microwave spectrum and structure of phosphaethene, CH2=PH

Abstract

The microwave spectra of phosphaethene (methylenephosphine) and five of its isotopic species have been observed and assigned in the region 5-125 GHz. Rotational constants and moments of inertia have been determined for 12CH2PH, 13CH2PH, 12CD2PD, 12CD2PH, ( Z )-12CHDPH and ( E )-12CHDPH. The moments of inertia have been used to determine the following structural parameters: r P-H= 1.425Å; rC-P= 1.671Å; rC-H,= 1.082Å; <HCP(Z) = 124.5º; <HCP(E) = 119.1º; <CPH = 95.5º. The dipole moment components have been determined as µa = 0.7233(7) D and µb = 0.4657(ll) D.