Matrix isolation studies of monomeric boron trisulphide

Abstract

The i.r. spectrum of diboron trisulphide isolated in argon and nitrogen matrices is reported. The use of partial isotopic substitution (¹⁰B/¹¹B and ³²S/³⁴S) enables the observed bands to be assigned to in-phase and out-of-phase vibrations of two –BS residues in a non-linear arrangement. This, coupled with mass spectrometric evidence and the assumption of linear SB–S linkages, show the shape of monomeric B₂S₃ to be based on a planar C_2v molecule with a BSB bond angle of ca. 120°.