Microwave spectrum, dipole moment and substitution structure of thiete

Abstract

The microwave spectra of thiete and nine isotopically substituted species have been investigated from 8 to 55 GHz. Rotational constants and centrifugal distortion constants have been fitted to the measured transition frequencies for each isotopic species. Measurements of the Stark splittings of three transitions for the parent species have yielded the components of the permanent electric dipole moment μa = 1.399(2) D, μb = 0.276(22) D and μtotal = 1.426(4) D. Planar moment of inertia, absence of any μc dipole component and harmonic behaviour of the lowest out-of-plane vibration established a planar equilibrium structure of the unsaturated four-membered ring. An almost complete substitution structure has been determined from the moments of inertia of all isotopic species. © 1984.