Jump to main content
Jump to site search


N-Methylcarbamoyl azide: spectroscopy, X-ray structure and decomposition via methylcarbamoyl nitrene

Author affiliations

Abstract

N-Methylcarbamoyl azide Me(H)NC(O)N3 has been synthesized and structurally characterized. Both N3 and CH3 groups in the molecule adopt a syn conformation with the C[double bond, length as m-dash]O bond. Upon flash vacuum pyrolysis at 800 K, the azide mainly decomposes into Me(H)NNCO/N2 and MeNCO/HN3 through Curtius-rearrangement and a retro-ene reaction, respectively. In contrast, 193 and 266 nm laser photolysis of Me(H)NC(O)N3 in cryogenic matrices (Ar, Ne, and N2) leads to stepwise Curtius-rearrangement via the intermediacy of carbamoylnitrene Me(H)NC(O)N, for which two conformers with the CH3 group being in syn and anti conformations to the C[double bond, length as m-dash]O bond have been unambiguously identified by matrix-isolation IR spectroscopy. Triplet multiplicity of Me(H)NC(O)N (|D/hc| = 1.57 cm−1 and |E/hc| = 0.012 cm−1) and another two carbamoylnitrenes H2NC(O)N (|D/hc| = 1.59 cm−1 and |E/hc| = 0.018 cm−1) and Me2NC(O)N (|D/hc| = 1.55 cm−1 and |E/hc| = 0.016 cm−1) has been further established by matrix-isolation EPR spectroscopy. Subsequent visible light irradiation (420–460 nm) of Me(H)NC(O)N results in the exclusive formation of Me(H)NNCO. The molecular structures of Me(H)NC(O)N3 and Me(H)NC(O)N, multiplicities of the nitrene, and the underlying mechanism for the decomposition of the azide are reasonably explained with quantum chemical calculations by utilizing the B3LYP, CBS-QB3, CCSD(T), and CASPT2 methods.

Graphical abstract: N-Methylcarbamoyl azide: spectroscopy, X-ray structure and decomposition via methylcarbamoyl nitrene

Back to tab navigation

Supplementary files

Publication details

The article was received on 10 Apr 2017, accepted on 07 Jun 2017 and first published on 12 Jun 2017


Article type: Research Article
DOI: 10.1039/C7QO00277G
Citation: Org. Chem. Front., 2017, Advance Article
  •   Request permissions

    N-Methylcarbamoyl azide: spectroscopy, X-ray structure and decomposition via methylcarbamoyl nitrene

    H. Wan, H. Li, J. Xu, Z. Wu, Q. Liu, X. Chu, M. Abe, D. Bégué and X. Zeng, Org. Chem. Front., 2017, Advance Article , DOI: 10.1039/C7QO00277G

Search articles by author

Spotlight

Advertisements