Nascent Vibrational Energy Distribution of CS(X 1 Σ + ) Generated in the S( 1 D) + CS 2 Reaction

The internal energy distributions of reaction products are important information in clarifying the mechanism of chemical reactions. There are few reports of the nascent vibrational energy distribution of CS(X Σ ) generated in the S( D) + CS reaction. As long as S( D) is produced by photodissociation of CS , CS(X Σ ), as a product of the chemical reaction and as a photoproduct of CS is indistinguishable. In this study, S( D) was generated by the photolysis of OCS at 248 nm, where CS hardly dissociates, and CS(X Σ ) was generated only by the S( D) + CS reaction. The vibrational levels ″ = 0-6 of CS(X Σ ) were detected with laser-induced fluorescence (LIF) via the A Π-X Σ transition. The identical time profiles of the LIF intensities showed that all the vibrational levels were produced by the S( D) + CS reaction. The relative nascent vibrational populations of CS(X Σ ) determined from the area intensities of the excitation spectra are 1.00 ± 0.11/0.58 ± 0.06/0.31 ± 0.03/0.078 ± 0.009/0.013 ± 0.001/