Pyrolysis of 3-azidopropionitrile studied by UV photoelectron and matrix-isolation IR spectroscopies: Formation of ketenimine H2Cdouble bond; length as m-dashCdouble bond; length as m-dashNH

Pinto, R.M., Dias, A.A., Levita, G., Rodriques, P, Barros, M.T., Dyke, J.M. and Costa, M.L. (2012) Pyrolysis of 3-azidopropionitrile studied by UV photoelectron and matrix-isolation IR spectroscopies: Formation of ketenimine H2Cdouble bond; length as m-dashCdouble bond; length as m-dashNH. [in special issue: Light-Induced Processes in Cryogenic Matrices] Journal of Molecular Structure, 1025, 151-159. (doi:10.1016/j.molstruc.2012.04.055).

Abstract

The electronic structure, vibrational properties and pyrolysis behaviour of 3-azidopropionitrile (3APN, N3CH2CH2CN) are investigated using ultraviolet photoelectron spectroscopy (UVPES) and matrix-isolation infrared (IR) spectroscopy, supported by results from ab initio and DFT electronic structure calculations. 3APN is found to have an HOMO vertical ionisation energy (VIE) of 10.05 ± 0.02 eV and the strongest IR absorption bands located at 2173 and 1296 cm?1. Pyrolysis of the title compound revealed the presence of N2, HCN, CH3CN and ketenimine, H2Cdouble bond; length as m-dashCdouble bond; length as m-dashNH, among the decomposition products, the latter behaving as a reaction intermediate. From G3 computational results, 3-iminopropionitrile, CNsingle bondCH2CHdouble bond; length as m-dashNH, was found to be formed in competition with H2Cdouble bond; length as m-dashN ? CH2CN, through 160–180 kJ mol?1 energy barriers. On the basis of experimental evidence and G3 results, ketenimine is proposed as the dominant intermediate arising from further decomposition of both imine (CNsingle bondCH2CHdouble bond; length as m-dashNH) and H2Cdouble bond; length as m-dashNsingle bondCH2CN compounds

This record has no associated files available for download.

Contributors

Author: J.M. Dyke

Download statistics