The asymmetric rotor in electronic spectroscopy: Centrifugal distortion and electron spin coupling effects in the spectra of NH 2 and CH 2

Abstract

Centrifugal distortion constants and three spin-rotation interaction constants of NH 2 , X¯ , 2 B 1 are derived from the data of Dressler and Ramsay. The values of the spin-rotation constants are e aa = − 0.292 ± 0.007 cm −1 , e bb = −0.054 ± 0.007 cm −1 , and e cc = −0.001 ± 0.007 cm −1 , showing an asymmetry effect in the spin splitting, and are in good agreement with those predicted by Dixon on the basis of a single electron configuration wave function. The energy levels of the a, 1 A 1 state of CH 2 calculated with revised parameters are used as evidence that the a, 1 A 1 state is perturbed by the X¯ , 3 g − state and an estimate of the separation is given.