Zhuang Xiujuan, Zhang Limin, Wang Jinting, Ma Yuchao, Yu Shuqin, Liu Shilin, Ma Xinxiao
Department of Chemical Physics, University of Science and Technology of China, Hefei, Anhui 230026, China.
J Phys Chem A. 2006 May 18;110(19):6256-60. doi: 10.1021/jp060533f.
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.
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。
