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(2D), with the simplest alkyne, C2H2, was investigated for the first time under single-collision conditions in crossed beam experiments with mass spectrometric detection. The experimental results combined with electronic structure calculations and RRKM predictions allow us to identify cyanomethylene (HCCN) as the main primary reaction product and to establish its formation dynamics. The identification of the N/H exchange channel suggests that the title reaction is a good candidate to explain formation of nitriles in the upper atmosphere of Titan.