Photolysis of matrix-isolated acetyl bromide and the infrared spectrum of the 1:1 molecular complex of hydrogen bromide with ketene in solid argon

Abstract

Abstract Ketene and HBr were generated by photolysis of acetyl bromide in an argon matrix. Of the photolysis products, ketene and HBr were trapped in the same matrix cage to form a 1:1 molecular complex. The HBr stretching mode in the complex was observed at 2396 cm −1 , which was displaced to 160 cm −1 below the frequency of the monomer HBr fundamental in solid argon. The DBr stretching frequency in the ketene- d 2 -DBr complex produced on photolysis of acetyl bromide- d 3 was observed at 1717 cm −1 , which was displaced to 120 cm −1 bewlo the frequency of the monomer DBr fundamental in solid argon. After the matrices were annealed, these absorptions were shifted to 2383 and 1708 cm −1 , respectively.