Electron Spin Resonance Study of the Photolytic Decomposition of HN3 in Inert Matrices at 4.2°K

Abstract

The only paramagnetic species observed amongst the products of the photolytic decomposition of hydrazoic acid, HN3, in Ar, Kr, and Xe matrices at 4.2°K are NH2 and an unidentified species which contains one hydrogen atom and possesses a hydrogen hyperfine coupling constant aHiso=23.8 G and giso∼2.010. The NH2 is probably produced by photolytic decomposition of HN3 aggregates. Our experiments have shown that the production of paramagnetic species is critically temperature dependent as witnessed by the fact that if there is poor thermal contact between the matrix sample and the coolant, then in addition to the above-mentioned paramagnetic species, H and N atoms are also formed. The H and N atoms appear to be formed as a result of the diffusion of NH, the primary product of the photodecomposition of HN3, followed by unidentified secondary processes and not by direct photolytic decomposition of HN3 or NH.