Photoreactivity on a water ice surface: cyanoacetylene (HC3N) reaction with atomic oxygen issued from the photodissociation of ozone (O-3) at 255 nm

Cyanoacetylene (HC3N) and ozone (O-3) were co-adsorbed on different sites o f a water ice surface and ozone was selectively irradiated with a YAG laser at 255 nm at 20 and 60 K. Two products were observed by FTIR spectroscopy, H2O2 resulting from the direct reaction between the ice surface and atomic oxygen, and cyanoketene resulting from the reaction of cyanoacetylene and atomic oxygen. The cyanoketene was characterized in argon matrix by laser a nd broad band irradiations from a co-deposition of two mixtures (O-3/Ar and HCcN/Ar) at 7 K. (C) 2001 Elsevier Science B.V. All rights reserved.