Microwave Spectrum of 1,1‐Difluoroethane

Abstract
The spectrum of 1,1‐difluoroethane has been investigated over the region 18 000 Mc to 38 000 Mc with a conventional Stark‐modulation spectrometer. This molecule is a moderately asymmetric rotor of the oblate type with components of its dipole moment along the A and C axes. About 30 lines have been identified with the aid of the Stark effect and an approximate model for the molecule. The analysis yields the following rotational constants: A=9491.95 Mc; B=8962.65 Mc; C=5170.43 Mc; x=0.75504. The barrier hindering internal rotation has been determined as (1.25±0.20)×103 cm—1 from intensity ratio measurements of the torsional frequency.