Microwave Spectra of CHBr3 in the Region from 11 to 12.5 Centimeters

Abstract

The spectrum of rotational transition J=0→1 of bromoform has been estimated to lie in a 10‐cm region. In this region, however, the spectroscopy has not yet been studied because of small absorption. Some of the present authors (S. K., K. T., and S. H.) had examined its detectability by the preliminary experiment with a cavity spectrometer. In the present paper more precise measurement using an absorption cell of 9 meters in length and its analysis by means of the theory proposed by some of the authors (M. M. and T. I.) are described. Thirty‐two lines due to the hyperfine structure of the rotational transition were measured in the region from 2400 to 2660 mc/sec. The width of line was smaller than 2 mc/sec at 3 mmHg. The theory agreed well with the experiment. The value of the moment of inertia obtained here agrees with the result of electron diffraction, and this moment seems not to change appreciably by a low frequency deformation vibration. The quadrupole coupling constant of Br nucleus is nearly equal to that of CH₃Br molecule.