Electronic spectrum of trimethylamine borane: An isoelectronic analog of neopentane

Abstract

The vacuum ultraviolet spectra of trimethylamine borane and trimethylamine borane- d 3 have been recorded in the region 50 000 cm −1 to 78 000 cm −1. Two electronic transitions are present, both exhibiting long vibronic progressions. The effect of isotopic substitution upon the excited state frequencies indicates that the excitation is localized largely in the N-BH 3D( 3) part of the molecule. Tentative assignments to upper state orbitals having mixed valence and Rydberg character are suggested.