INFRARED SPECTRA OF THE AZIDE ION IN ALKALI HALIDE $MATRICES^{*}$

$^{*}$This work was supported by the Basic Research Group, U. S. Army Engineer Research and Development Laboratories, Fort Belvoir, Virginia, under Contract No. DA-44-009 ENG--4532.Author Institution: Department of Chemistry, Howard UniversityThe infrared spectra of the azide ion in KCl, KBr, KI and NaCl matrices have been observed from 4000 to 400 $cm{-1}$ using Perkin-Elmer models 21 and 112 spectrometers with LiF, NaCl and KBr prisms. A comparison has been made of the spectra of samples grown from aqueous solution with those prepared of the pressed disk technique. Particular attention has been paid to the dependence of the vibrational frequencies on the nature of the matrix and on the temperature. The various contributions to the interionic potential function will be considered in relation to the observed frequency shifts. It is suggested that the study of vibrational frequency variations of an “impurity” ion in a lattice provides a useful method of measuring interior forces