The Normal Vibrations of Polyatomic Molecules as Calculated by Urey-Bradley Field. II. Vibrations of Polythene, Ethane, and Their Deuterium Compounds

Assuming the Urey-Bradley field as the type of intramolecular potential equations to calculate five optically active frequencies of polythene molecule were derived. If we assume as force constants KCH=4.2, HHCH=0.15, FHH=0.1, FHC=0.4, FHH′=0 and FHC′=−0.05 (105 dynes/cm), the observed frequencies of (CH2)n and (CD2)n as well as those of CH4, CD4, C2H6, C2D6, etc., were explained satisfactorily.