MICROWAVE-SPECTRUM OF 1-PHOSPHAPROPYNE, CH3C=P - MOLECULAR-STRUCTURE, DIPOLE-MOMENT, AND VIBRATION-ROTATION ANALYSIS

The J = 4 ← 3 and J = 3 ← 2 rotational transitions of 1-phosphapropyne, CH3CP, between 26.5 and 40 GHz have been studied by microwave spectroscopy. The spectrum shows the characteristic vibration-rotation satellite patterns associated with a C3v symmetric rotor. Apart from the most abundant isotope variant, the species 12CD312C31P, 12CD2H12C31P, 12CH2D12C31P, 13CH312C31P, 12CH313C31P, 13CD312C31P, and 12CD313C31P have also been studied. For 12CH312C31P the rotational constants B0 = 4991.339 ± 0.003 MHz, DJ = 0.823 ± 0.092 kHz, DJK = 66.59 ± 0.18 kHz have been determined. From these data the following structural parameters have been derived: rs(CH) = 1.107 ± 0.001 A ̊, ∠s(HCC) = 110.30 ± 0.09°, rs(CC) = 1.465 ± 0.003 A ̊, r0(CP) = 1.544 ± 0.004 A ̊. The dipole moment has been determined as 1.499 ± 0.001 D by analysis of the Stark effect of the J = 3 ← 2, |K| = 1 line. The vibrational satellites (vs = 1, 2, and 3) have been studied and various vibration-rotation parameters derived. © 1979.