FTIR studies of O(3P) atom reactions with CSe2, SCSe, and OCSe

Abstract

The overall rate coefficients of the reactions of CSe2, SCSe, and OCSe with O(3P) atom have been determined to be kCSe2 = (1.4 ± 0.2) × 10-10 cm3 molecule-1 s-1, kSCSe = (2.8 ± 0.3) × 10-11 cm3 molecule-1 s-1, and kOCSe = (2-4 ± 0.3) × 10-11 cm3 molecule -1 s-1 at 301-303 K using Fourier transform infrared (FTIR) absorption spectroscopy. The measurements have been accomplished by calibrating against the literature value of the rate coefficient for O( 3P) with CS2 (4 × 10-12 cm3 molecule-1s-1). A product channel giving OCSe in 32.0 ± 4.2% yield has been found for the O + CSe2 reaction. Although CO was also detected, its generation could be attributed to subsequent reactions of OCSe with O atoms. The corresponding reaction for O + SCSe gives OCS and OCSe as observable products, with their yields given as 32.2 ± 4.5 and 30.2 ± 3.3%, respectively. Computational studies using UB3LYP/aug-cc-PVTZ methods have been used particularly to determine the reaction pathways for the channels in which OCS or OCSe is produced. © 2005 American Chemical Society.