Cyanomethylene formation from the reaction of excited nitrogen atoms with acetylene: A crossed beam and ab initio study

The reaction of excited nitrogen atoms, N(D-2), with the simplest alkyne, C 2H2, was investigated for the first time under single-collision conditions in crossed beam experiments with mass spectrometric detection. The experime ntal results combined with electronic structure calculations and RRKM predi ctions allow us to identify cyanomethylene (HCCN) as the main primary react ion product and to establish its formation dynamics. The identification of the N/H exchange channel suggests that the title reaction is a good candida te to explain formation of nitriles in the upper atmosphere of Titan.