The Infra‐Red Absorption by Hydrogen Selenide, Deuterium Selenide and Deutero‐Hydrogen Selenide

The infra‐red spectra of H2Se, D2Se and HDSe have been measured and the positions of the three fundamental frequencies for each molecule have been determined. These are; for H2Se v1 = 2260 cm—1, v2 = 1074 cm—1, v3 = 2350 cm—1; for D2Se, v1 = 1630 cm—1, v2 = 745 cm—1, v3 = 1696 cm—1; for HDSe, v1 = 1691 cm—1, v2 = 905 cm—1 and v3 = 2352 cm—1. Interpretation of the observed data has led to the adoption of an obtuse model where the H–Se–H bond angle is slightly in excess of 90°. The H–Se distances are evaluated to be 1.6A and the H–H distance is equal to 2.3A. The product relations of Redlich are made use of as a verification of a correct assignment of frequencies and for a correct determination of the band centers.