Spin-rotation hyperfine structure in the rotation spectrum of ⁷⁷Se-seienoformaldehyde

Measurement and analysis of hyperfine splitting in the microwave spectrum of selenoformaldehyde (CH₂⁷⁷Se) has yielded⁷⁷Se spin-rotation constants, which are compared with constants calculated using the coupled Hartree-Fock technique and with constants of homologous molecules. Rotational and centrifugal distortion constants for CH₂⁷⁷Se have been derived from the resultant pure rotational frequencies. An empirical prediction of spin rotation constants has been made for telluroformaldehyde (CH₂¹²⁵Te).