Reaction path of UV photolysis of matrix isolated acetyl cyanide: formation and identification of ketenes, zwitterion, and keteneimine intermediates.
Irradiations at lambda > 180 nm and lambda > 230 nm of CH3COCN (CD3COCN) trapped in an argon matrix at 10 K have been performed and monitored by Fourier transform infrared spectroscopy. For both wavelengths, the first photoreaction product is acetyl isocyanide. At lambda > 180 nm acetonitrile and methyl isocyanide are obtained as final products. They are formed by photolysis of acetyl isocyanide and acetyl cyanide, respectively. Unstable intermediates, such as ketene:HCN and ketene:HNC complexes, H2CNCH zwitterion, and H2C2NH keteneimine, not observed in the gas phase, are trapped and identified at our experimental temperature. The complexes have an L-shaped structure with a hydrogen bond between the oxygen atom of ketene and the hydrogen atom of HCN or HNC. A pathway process is proposed and compared with the ones determined in the ground state by ab initio calculations.
Guennoun
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Z
Laboratoire de Physique des Interactions Ioniques et Moléculaires, UMR 6633 Equipe de Spectrométries et Dynamique Moléculaires, Université de Provence, Centre de St-Jérôme case 252, 13397 Marseille Cedex 20, France.
Couturier-Tamburelli
I
I
Combes
S
S
Aycard
J P
JP
Piétri
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N