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An investigation of the photodissociation of methylazide at wavelengths from 292 nm to 325 nm is presented. Emission spectra and lifetime analysis show the existence of the triplet CH3N radical. A simple kinetic model is proposed to explain the observed fluorescence real time profile, which reflects the vibrational relaxation of hot radical at high pressures. The photodissociation dynamics of methylazide seems complex. The predominant channel is likely to produce CH2NH via concerted 1,2‐hydrogen shift and N2 extrusion process. The triplet CH3N comes from a minor spin‐forbidden channel which involves possibly strong interaction between the low‐lying excited singlet and triplet states of methylazide.

The vibrationally resolved laser‐induced fluorescence spectra of the A 3E↔X 3A2 system of CH3N radical were obtained experimentally. The dispersed spectra at different vibrationally excited states confirm that the system studied belongs to the CH3N radical. From the vibrational progressions in the excitation spectrum, following vibrational frequencies of the A 3E state were determined: ν1′=2943 cm−1, ν2′=1239 cm−1, ν3′=759 cm−1, and ν5′=1500 cm−1. In addition, the lifetimes of the A 3E state at four vibrational states (ν3′=0, 3, 4, and 6) were measured, which are, respectively 292.8±1.2, 203.4±1.2, 188.2±0.5, and 157.2±0.5 ns at a total pressure of 1.7 Torr. Our experiments show that the A 3E state is bound at least up to 4800 cm−1 and is relatively free from photochemistry.