Infrared Spectrum and Structure of Gaseous Al2O

Abstract

The infrared absorption spectrum of Al₂O trapped in solid argon and krypton matrices has been observed. It is possible from the observed spectra and isotope shifts for Al₂¹⁶O and Al₂¹⁸O to conclude that the molecular symmetry of Al₂O is C_2v and that the Al–O–Al angle is probably not far from 145°. Force constants and the bending frequency v₂ have been calculated. Reanalysis of the ultraviolet spectra of exploding aluminum wires provides additional support both for the bent structure and for the calculated value of v₂. The Al–O bond distance is estimated to be 1.66 Å. The three fundamental frequencies for Al₂¹⁶O in an argon matrix are (in cm^—1): v₁ = 715, v₂ = [238]; v₃ = 994.