Acta Phys. -Chim. Sin. ›› 2004, Vol. 20 ›› Issue (05): 535-539.doi: 10.3866/PKU.WHXB20040518

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The Rate Constants of the Reactions of NCO with SO2 or CS2

Zhang Zhi-Qiang;Hu Chang-Jin;Pei Lin-Sen;Chen Cong-Xiang;Chen Yang   

  1. Laboratory of Bond Selective Chemistry, Department of Chemical Physics, University of Science and Technology of China, Hefei 230026
  • Received:2003-11-12 Revised:2004-01-27 Published:2004-05-15
  • Contact: Chen Yang

Abstract: The reactions of NCO with SO2 or CS2 in gas phase under total pressure of 2660 Pa and 298 K were studied by laser photolysis/laser induced fluorescence (LP/LIF).The NCO radicals were produced by laser photolysis of CHBr3 at 266 nm followed by the reaction of the produced CH in the photolysis reaction with NO. The relative concentration of ground states NCO radicals were monitored by time resolved LIF spectra. From the results of time resolved measurements on the NCO radicals, the bimolecular rate constants for the reactions of NCO with SO2 and CS2 were obtained as (1.8±0.3)×10-11 and (3.1±0.4)×10-12 cm3•molecule-1•s-1, respectively. In addition, the two reactions were studied using ab initio calculations at the B3LYP/6-31+G(d) level. The results show that both are addition reactions and have the similar mechanism in which N atom of NCO radical attacks the central atom of SO2 or CS2 to form addition product.

Key words: NCO radical, Laser photolysis-laser induced florescence(LP-LIF), Rate constant of reaction