The thermal and UV photo-induced decomposition of azomethane, CH3N=NCH3, was investigated by means of reflection absorption infrared spectroscopy (RAIRS) and temperature-programmed desorption spectroscopy (TPD). The RAIRS data revealed that azomethane adsorbs in the trans-configuration mode on Rh(111) at 90 K. During thermal treatment, azomethane decomposes exclusively by N-N bond scission, yielding H2, N2, C2N2 and traces of HCN. Upon UV irradiation at 90 K, adsorbed azomethane undergoes tautomerization, forming formaldehyde methylhydrazone, CH3NHN=CH2. The important features of the post-irradiation TPD spectra are the significant suppression of C2N2 and N2 formation, and the appearance of the new products methylamine (CH3NH2) and CH4. C-N bond scission also occurred in the illuminated chemisorbed layer at 90 K.
ASJC Scopus subject areas
- Physics and Astronomy(all)
- Physical and Theoretical Chemistry