Infra-Red Absorption Bands in the Spectrum of Deutero-Formaldehyde

The spectrum of deutero-formaldehyde in the infra-red has been studied from 2.0μ to 13.0μ and seven absorption bands have been found. With these data and the data on the spectrum of the ordinary formaldehyde available it has been possible, making use of the product relations of Redlich, to identify with considerable certainty the fundamental frequencies of the H2CO and D2CO molecules, respectively, as: ν1 = 2780 cm—1, ν2 = 1750 cm—1, ν3 = 2875 cm—1, ν4 = 1503 cm—1, ν5 = 1278 cm—1, ν6 = 1165 cm—1, and ν1′ = 2056.4 cm—1, ν2′ = 1700 cm—1, ν3′ = 2160.3 cm—1, ν4′ = 1106.4 cm—1, ν5′ = 990.2 cm—1 and ν6′ = 938.0 cm—1. With this identification the valence force constants for the formaldehyde molecules have been computed.