Microwave Spectrum of Formaldehyde I. K-type Doubling Spectra

Abstract

Microwave spectral lines for the direct transitions between the K-type doublets were measured from 3 kMc to 40 kMc for H₂CO and for its isotopically substituted molecules HDCO, H₂C¹³O and H₂CO¹⁸. The observed spectra and the previously reported data for H₂CO were analyzed by a digital computer by the use of Kivelson and Wilson’s method for the centrifugal distortion correction.
The asymmetry parameter b and B–C were obtained for each isotopic species as follows:
(Remark: Graphics omitted.)
It was found that the observed frequencies fit well to those calculated from the centrifugal distortion constants which were derived by the vibration-rotation interaction theory.