Low-Temperature Matrix Isolation and Photolysis of BCl₂N₃:  Spectroscopic Identification of the Photolysis Product ClBNCl

Abstract

BCl 2 N 3 was isolated in a low-temperature argon matrix, and its FTIR spectrum was measured. Ab initio calculations were carried out to support the identification of the IR spectrum, and splitting due to the natural abundances of 10 B and 11 B was observed. The experimental infrared frequencies and assignments are as follows: 2170 cm -1, the N 3 asymmetric stretch; 1350 cm -1, the BN stretch; 1053 cm -1, the N 3 symmetric stretch; 968 cm -1, the BCl stretch. Upon UV photolysis, the BCl 2 N 3 peaks decreased and new peaks at 2034 and 2087 cm -1 with relative integrated intensities of 4:1 appeared. Ab initio calculations were carried out and support the assignment of these features to the BN stretches in the 10 B and 11 B isotopomers of ClBNCl. This intermediate is consistent with the photolytic intermediate generated during the photolysis of B(N 3 ) 3, and the photolytic mechanism is discussed.