Theory of Pure Rotational Transitions in Doubly Degenerate Torsional States of Ethane

Abstract
Pure rotational transitions in doubly degenerate torsional states of C2 H6, with selection rules ΔK=0, ΔJ=0,±1, are shown to be made allowed by Coriolis interaction between torsion and dipole-allowed vibrations. Expressions for integrated intensities are presented from which strengths of lines in the millimeter region are calculated.