ESR and optical spectroscopy of matrix-isolated ethylnitrene

Publisher Website
Google Scholar
Abstract
The ethylnitrene radical CH3CH2N has been produced by the interaction of gaseous ethylazide with metastable N2 or Ar generated in a microwave discharge, and has been trapped in N2 and Ar matrices at 10 K. The UV absorption spectrum in solid nitrogen consists of a series of 11 bands beginning at 335 nm with an average vibrational interval of 320 cm−1. Intensity alternations suggest that two different vibrations are excited in the transition, probably a C–C–N bend corresponding to the observed spacing and a C–N stretch with vibrational frequency near 640 cm−1. The electron spin resonance (ESR) spectrum at 8300 G indicates that ethylnitrene has a triplet ground state with zero‐field splitting parameters D=1.67 cm−1, and E=0.0035 cm−1 in a nitrogen matrix. The hyperfine splittings differ slightly in the x and y lines and have the average values of 16.0 G for N and 30.6 G for the methylene H. The spectral features associated with ethylnitrene were not observed through direct photolysis of the parent ethylazide either during or after deposition. The data lend support to the conclusion that earlier assignments of the ESR spectrum of methylnitrene, CH3N, are incorrect, and may provide a lower limit to ‖D‖ for that molecule in the matrix.