The 4-methyl-3-azabenzyl radical was generated from 2,5-lutidine in a corona excited supersonic expansion, and its fluorescence emission spectrum was recorded. Two possible radical isomers could form by loss of an H atom from either methyl group in 2,5-lutidine. Theoretical studies of both isomers confirmed the only species observed was 4-methyl-3-azabenzyl. The emission spectrum corresponded to the D-1 -> D-0 transition, with a strong origin peak and several vibronic bands. The origin transition is located at 21 401 cm(-1), in good agreement with a previous assignment, and calculated vibrational energies were in good agreement experimental vibrational energies. (C) 2015 Elsevier B.V. All rights reserved.