The Two Competitive Photodissociation Channels in Cyano Carbonyls

Feb 10, 2000 - The Two Competitive Photodissociation Channels in Cyano Carbonyls (NCC(O)X, X = CH3, CH(CH3)2, C(CH3)3, OCH3) at 193 nm. A Study by Pho...
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J. Phys. Chem. A 2000, 104, 1920-1929

The Two Competitive Photodissociation Channels in Cyano Carbonyls (NCC(O)X, X ) CH3, CH(CH3)2, C(CH3)3, OCH3) at 193 nm. A Study by Photofragment Translational Energy Spectroscopy Alan Furlan, Heiner A. Scheld, and J. Robert Huber* Physikalisch-Chemisches Institut der UniVersita¨ t Zu¨ rich, Winterthurerstrasse 190, CH-8057 Zu¨ rich, Switzerland ReceiVed: September 29, 1999; In Final Form: December 20, 1999

The photodissociation of a series of four cyano carbonyl compounds NCC(O)X with X ) methyl, isopropyl, tert-butyl, and methoxy was studied after excitation at 193 nm using photofragment translational energy spectroscopy. For all the fragments generated (OCCN, XCO, CO, CN, X) the kinetic energy distributions were measured and the two radical decay channels, NCC(O)X f CN + OCX and NCC(O)X f OCCN + X, were identified. Dissociation leading to CN + OCX is the main decay path (∼85%) for acetyl cyanide (X ) methyl), but is the minor pathway for X ) isopropyl (30%), X ) tert-butyl (17%), and X ) methoxy (