Crossed Molecular Beams Study on the Formation of Vinylacetylene in Titan’s Atmosphere

• DOI: 10.1021/jp9032595
• Publication Date: 2009-06-12T17:44:06Z
• Authors: Fangtong Zhang; Yong Seol Kim; Ralf I. Kaiser; Sergey P. Krishtal; Alexander M. Mebel
• Keywords: 01 natural sciences; 7. Clean energy; 0104 chemical sciences

The reaction of ground-state ethynyl radicals, C(2)H(X(2)Sigma(+)), with d(4)-ethylene, C(2)D(4)(X(1)A(g)), was investigated at a collision energy 20.6 +/- 0.4 kJ mol(-1) utilizing the crossed-beams technique. Combined electronic structure calculations, our results elucidate that this follows indirect dynamics via doublet radical complex. is initiated by barrierless addition to carbon atom d(4)-ethylene molecule form C(4)HD(4) intermediate. latter long-lived compared its rotational period and decomposes tight exit transition state d(3)-vinylacetylene product (HCCC(2)D(3)) plus deuterium while conserving group; center-of-mass angular distribution suggests leaves almost perpendicularly plane fragmenting overall found be exoergic 94 20 mol(-1); value agrees nicely computational data 103 5 mol(-1). This study indicates analogous vinylacetylene (HCCC(2)H(3)) can synthesized in low-temperature environment such as Titan's atmosphere neutral-neutral radicals ubiquitous ethylene. similarity between isoelectronic cyano radical, CN(X(2)Sigma(+)), ethylene-yielding vinylcyanide (C(2)H(3)CN) also discussed.