Detection of atomic bromine (4p5 2P ; J = 1/2, 3/2) by two-photon laser-induced vacuum ultraviolet emission

Nascent Vibrational Energy Distribution of CS(X1Σ+) Generated in the S(1D) + CS2 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(X¹Σ⁺) generated in the S(¹D) + CS₂ reaction. As long as S(¹D) is produced by photodissociation of CS₂, CS(X¹Σ⁺), as a product of the chemical reaction and as a photoproduct of CS₂ is indistinguishable. In this study, S(¹D) was generated by the photolysis of OCS at 248 nm, where CS₂ hardly dissociates, and CS(X¹Σ⁺) was generated only by the S(¹D) + CS₂ reaction. The vibrational levels v″ = 0-6 of CS(X¹Σ⁺) were detected with laser-induced fluorescence (LIF) via the A¹Π-X¹Σ⁺ transition. The identical time profiles of the LIF intensities showed that all the vibrational levels were produced by the S(¹D) + CS₂ reaction. The relative nascent vibrational populations of CS(X¹Σ⁺) 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/<0.002/<0.002 (the values for v″ = 5 and 6 are the upper limits) for v″ = 0/1/2/3/4/5/6. The distribution agrees well with the statistical (prior) distribution.