Group vibrations and the vibrational analysis of molecules containing methylene groups. Part I. The basic equations and the application of the method to methylene dichloride and cyclopropane

Abstract

The vibrations of the methylene group first considered by King have been reexamined; and the group factorization procedure previously applied to molecules containing methyl groups has now been extended to molecules containing methylene groups. The vibrational analysis of such molecules can be simplified by factoring from the secular determinant those frequencies that are characteristic of the symmetric and antisymmetric CH2 stretching, and the [Formula: see text] angle bending modes. Corrections are then applied to the G and F matrices to account for the interactions with the molecular framework of the CH2 'rocking', and [Formula: see text] angle deformation modes, where the atoms X may form part of a ring system.