The formation of nitrites in hydrocarbon-rich atmospheres of planets and their satellites: Laboratory investigations by the crossed molecular beam technique

Crossed molecular beam experiments of cyano radicals, CN(X(2)Sigma (+)), re acting with unsaturated hydrocarbons have been performed to investigate syn thetic routes to nitriles formation in hydrocarbon-rich atmospheres of plan ets and their moons. We have verified that all cyano radical reactions with acetylene, ethylene, methylacetylene, allene, benzene, and dimethylacetyle ne proceed without entrance barrier, have exit barriers well below the ener gy of the reactant molecules, and are strongly exothermic. The identificati on of the CN versus H atom exchange channel makes these reactions compellin g candidates to synthesize unsaturated nitriles in solar system environment s. Some of these nitriles, hitherto unobserved in our solar system, now rep resent an ideal target to be detected in the future Cassini-Huygens mission to Titan.