通过B2Σu+和C2Σg+电子态对CS2+光解离光谱的研究。

Study on the photodissociation spectra of CS2+ via B2Sigma u+ and C2Sigma g+ electronic states.

作者信息

Zhuang Xiujuan, Zhang Limin, Wang Jinting, Ma Yuchao, Yu Shuqin, Liu Shilin, Ma Xinxiao

机构信息

Department of Chemical Physics, University of Science and Technology of China, Hefei, Anhui 230026, China.

出版信息

J Phys Chem A. 2006 May 18;110(19):6256-60. doi: 10.1021/jp060533f.

DOI:10.1021/jp060533f

PMID:16686459

Abstract

The photodissociation spectra of CS(2)(+) ions via B(2)Sigma(u)(+) and C(2)Sigma(g)(+) electronic states have been studied by using two-photon excitation, where the parent CS(2)(+) ions were prepared by [3 + 1] REMPI (resonance-enhanced multiphoton ionization) at 483.2 nm from the jet-cooled CS(2) molecules. The [1 + 1] photodissociation spectrum of CS(2)(+) via the B(2)Sigma(u)(+)(upsilon(1)upsilon(2)0) <-- X(2)Pi(g,3/2)(000) transition was obtained by scanning the dissociation laser in the wavelength range of 270-285 nm and detecting the signal of both S(+) and CS(+). The [1 + 1'] photodissociation spectra of CS(2)(+) were obtained by fixing the first dissociation laser at 281.94 or 277.15 nm to excite the B(2)Sigma(u)(+) (000 or 100) <-- X(2)Pi(g,3/2)(000) transitions and scanning the second dissociation laser in the range of 606-763 nm to excite C(2)Sigma(g)(+)(upsilon(1)upsilon(2)0) <-- B(2)Sigma(u)(+)(000,100) transitions. New spectroscopic constants of nu(1) = 666.2 +/- 2.5 cm(-1), nu(2) = 363.2 +/- 1.9 cm(-1), chi(11) = -5.5 +/- 0.1 cm(-1), chi(22) = 1.6 +/- 0.1 cm(-1), chi(12) = -8.6 +/- 0.2 cm(-1), and k(122) = 44.9 +/- 2.5 cm(-1) (Fermi resonance constant) for the C(2)Sigma(g)(+) state are deduced from the [1 + 1'] photodissociation spectra. On the basis of the [1 + 1] and [1 + 1'] photodissociation spectra, the wavelength and level dependence of the product branching ratios CS(+)/S(+) has been found and the dissociation dynamics of CS(2)(+) ions via B(2)Sigma(u)(+) and C(2)Sigma(g)(+) electronic states are discussed.

摘要

通过双光子激发研究了CS₂⁺离子经由B₂Σᵤ⁺和C₂Σg⁺电子态的光解离光谱，其中母体CS₂⁺离子是通过在483.2 nm处对喷射冷却的CS₂分子进行[3 + 1]共振增强多光子电离（REMPI）制备的。通过在270 - 285 nm波长范围内扫描解离激光并检测S⁺和CS⁺的信号，获得了CS₂⁺经由B₂Σᵤ⁺(υ₁υ₂0) ← X₂Πg,3/2(000)跃迁的[1 + 1]光解离光谱。通过将第一束解离激光固定在281.94或277.15 nm以激发B₂Σᵤ⁺(000或100) ← X₂Πg,3/2(000)跃迁，并在606 - 763 nm范围内扫描第二束解离激光以激发C₂Σg⁺(υ₁υ₂0) ← B₂Σᵤ⁺(000,100)跃迁，获得了CS₂⁺的[1 + 1']光解离光谱。从[1 + 1']光解离光谱中推导出C₂Σg⁺态的新光谱常数：ν₁ = 666.2 ± 2.5 cm⁻¹，ν₂ = 363.2 ± 1.9 cm⁻¹，χ₁₁ = -5.5 ± 0.1 cm⁻¹，χ₂₂ = 1.6 ± 0.1 cm⁻¹，χ₁₂ = -8.6 ± 0.2 cm⁻¹，以及k₁₂₂ = 44.9 ± 2.5 cm⁻¹（费米共振常数）。基于[1 + 1]和[1 + 1']光解离光谱，发现了产物分支比CS⁺/S⁺的波长和能级依赖性，并讨论了CS₂⁺离子经由B₂Σᵤ⁺和C₂Σg⁺电子态的解离动力学。