193 nm photodissociation of carbonyl cyanide CO(CN)2 probed by the CN(v,J) fragment

The photodissociation of CO(CN)2 at 193 nm has been studied by probing the nascent CN fragments. Two energetically different CN species were identified, a rotationally and vibrationally hot one characterized by Tr∼2300 K and Tv∼3600 K, and a cold one exclusively in v=0 with Tr∼410 K. The hot CN together with OCCN stems from the α-cleavage while the cold CN, which accounts for about 18% of all CN fragments, is from the spontaneous secondary decay OCCN→CN+CO thus confirming the three-body decay to be a sequential process.