MICROWAVE SPECTRA OF ETHYLPHOSPHINE

Abstract

The microwave (12.5-40.0 GHz) spectra have been recorded and assigned to the gauche and trans isomers. The following rotational constants have been determined (in MHz): $A = 25 610 \pm 58$, $B = 5016.49 \pm 0.03$, $C =4600.29 \pm 0.03$ for the trans isomer, and $A = 25 572.15 \pm 0.04$, $B = 5126.24 \pm 0.01$, $C = 4658.03 \pm 0.01$ for the gauche isomer. The trans isomer was found to have the following dipole moment components: $\mu_{a} = 1.22 \pm 0.08 D$, $\mu_{b} = 0.16 \pm 0.05 D$, with a total dipole moment of $\mu_{t} = 1.23 \pm 0.09 D$. The gauche isomer was found to have the following dipole moment components: $\mu_{a} = 0.87 \pm 0.03 D$, $\mu_{b} = 0.69 \pm 0.02 D$, $\mu_{c}= 0.48 \pm 0.02 D$ with a total dipole moment of $\mu_{t} = 1.21 \pm 0.04 D$. These data will be discussed relative to the structural implications.