Kinetic studies of the reactions of methyleneaminylium and dideuteromethyleneaminylium radicals with nitrogen and hydrogen atoms

Absolute rate constants for the reactions of H{sub 2}CN and D{sub 2}CN with N atoms have been measured by using the discharge flow-mass spectrometry technique between 200 and 363 K. No isotope effect was observed. The results are as follows (10{sup {minus}11} cm{sup 3} s{sup {minus}1}): k{sub 1}(200 K) = 3.9 {plus minus} 2.2, K{sub 1}(298 K) = 4.4 {plus minus} 1.4, k{sub 1}(363 K) = 6.7 {plus minus} 2.0. The reactions of D{sub 2}CN with H and with D atoms were also studied. This study represents the first determination of the rate constants for these reactions. The significance of these processes in models of the atmospheres of Titan and Jupiter and in the chemistry of circumstellar and interstellar clouds is discussed; their role in laboratory experiments on active nitrogen/hydrocarbon reactions is also considered.