Two Bands in the Infrared Spectrum of Formaldehyde

Abstract

Two infrared bands of the type arising from oscillations of the electric moment normal to the axis of symmetry have been measured under high dispersion and identified as the two oscillations which are at right angles to each other and which in Sutherland and Dennison's notation are v₅ and v₆. Their centers are respectively at 1278 cm^‐1 and 1165 cm^‐1. The anomalous spacing between the principal rotation lines is accounted for on the basis of an interaction between rotation and the two oscillations which are only slightly anisotropic.