Spectra and structure of small‐ring molecules. XLI. Microwave spectrum of 3‐phospholene Academic Article uri icon


  • The microwave spectra of 3-phospholene and 3-phospholene-1-d1 were recorded from 12-40 GHz and 26.5-40 GHz, respectively. Only A-type transitions were observed. The R branch assignments have been made for the ground state of the -d1 molecule, and the ground, first, and second excited states of the ring-puckering mode for the "light" molecule. It is shown that the skeletal atoms of the five-membered ring are noncoplanar and the ring is puckered by an angle of approximately 18°. Additionally, it is shown that the most stable form of the molecule is the "endo" form with the P-H bond directed toward the double bond. From relative intensity measurements it is concluded that the first excited state of the ring-puckering mode has a frequency of 160±15 cm-1. From measurements of the Stark effect for the 3-phospholene molecule the dipole moment components were determined to be |μa| = 1.10±0.02 D, |μb| = 0.0D (assumed) and |μc| = 0.16±0.05 D with the total dipole moment being |μt| = 1.11±0.02 D. These results are compared to other similar molecules. © 1980 American Institute of Physics.

author list (cited authors)

  • Durig, J. R., Streusand, B. J., Li, Y. S., Richardson, L., & Laane, J.

citation count

  • 15

publication date

  • December 1980