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; r_C-P= 1.671Å; r_C-H,= 1.082Å; <HCP_(Z) = 124.5º; <HCP_(E) = 119.1º; <CPH = 95.5º. The dipole moment components have been determined as µ_a = 0.7233(7) D and µ_b = 0.4657(ll) D.