Theoretical analysis of photoinduced H-atom elimination in thiophenol

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	Theoretical analysis of photoinduced H-atom elimination in thiophenol
	Venkatesan, T. S.1,2; Ramesh, S. G.1,3; Lan, Z.4; Domcke, W.1
刊名	JOURNAL OF CHEMICAL PHYSICS
	2012-05-07
卷号	136 期号:17
中文摘要	The photoinduced hydrogen elimination reaction in thiophenol via the conical intersections of the dissociative ¹πσ* excited state with the bound ¹ππ* excited state and the electronic ground state has been investigated with ab initio electronic-structure calculations and time-dependent quantum wave-packet calculations. A screening of the coupling constants of the symmetry-allowed coupling modes at the ¹ππ-¹πσ and ¹πσ-S₀ conical intersection shows that the SH torsional mode is by far the most important coupling mode at both conical intersections. A model including three intersecting potential-energy surfaces (S₀, ¹ππ, ¹πσ) and two nuclear degrees of freedom (SH stretch and SH torsion) has been constructed on the basis of ab initio* complete-active-space self-consistent field and multireference second-order perturbation theory calculations. The nonadiabatic quantum wave-packet dynamics initiated by optical excitation of the ¹ππ* and ¹πσ* states has been explored for this three-state two-coordinate model. The photodissociation dynamics is characterized in terms of snapshots of time-dependent wave packets, time-dependent electronic population probabilities, and the branching ratio of the ²σ/²π electronic states of the thiophenoxyl radical. The dependence of the timescale of the photodissociation process and the branching ratio on the initial excitation of the SH stretching and SH torsional vibrations has been analyzed. It is shown that the node structure, which is imposed on the nuclear wave packets by the initial vibrational preparation as well as by the transitions through the conical intersections, has a profound effect on the photodissociation dynamics. The effect of additional weak coupling modes of CC twist (ν_16a) and ring-distortion (ν_16b) character has been investigated with three-dimensional and four-dimensional time-dependent wave-packet calculations, and has been found to be minor.
英文摘要	The photoinduced hydrogen elimination reaction in thiophenol via the conical intersections of the dissociative (1)pi sigma* excited state with the bound (1)pi pi* excited state and the electronic ground state has been investigated with ab initio electronic-structure calculations and time-dependent quantum wave-packet calculations. A screening of the coupling constants of the symmetry-allowed coupling modes at the (1)pi pi-(1)pi sigma and (1)pi sigma-S-0 conical intersection shows that the SH torsional mode is by far the most important coupling mode at both conical intersections. A model including three intersecting potential-energy surfaces (S-0, (1)pi pi, (1)pi sigma) and two nuclear degrees of freedom (SH stretch and SH torsion) has been constructed on the basis of ab initio complete-active-space self-consistent field and multireference second-order perturbation theory calculations. The nonadiabatic quantum wave-packet dynamics initiated by optical excitation of the (1)pi pi and (1)pi sigma* states has been explored for this three-state two-coordinate model. The photodissociation dynamics is characterized in terms of snapshots of time-dependent wave packets, time-dependent electronic population probabilities, and the branching ratio of the (2)sigma/(2)pi electronic states of the thiophenoxyl radical. The dependence of the timescale of the photodissociation process and the branching ratio on the initial excitation of the SH stretching and SH torsional vibrations has been analyzed. It is shown that the node structure, which is imposed on the nuclear wave packets by the initial vibrational preparation as well as by the transitions through the conical intersections, has a profound effect on the photodissociation dynamics. The effect of additional weak coupling modes of CC twist (nu(16a)) and ring-distortion (nu(16b)) character has been investigated with three-dimensional and four-dimensional time-dependent wave-packet calculations, and has been found to be minor. (C) 2012 American Institute of Physics. [http://dx.doi.org/10.1063/1.4709608]
学科主题	多相催化转化
WOS标题词	Science & Technology ; Physical Sciences
类目[WOS]	Physics, Atomic, Molecular & Chemical
研究领域[WOS]	Physics
关键词[WOS]	PHOTOFRAGMENT TRANSLATIONAL SPECTROSCOPY ; NEAR-ULTRAVIOLET PHOTOLYSIS ; INTRAMOLECULAR ORBITAL ALIGNMENT ; PHOTODISSOCIATION DYNAMICS ; CONICAL INTERSECTIONS ; UV PHOTOLYSIS ; (1)PI-SIGMA-ASTERISK STATES ; SUBSTITUTED PHENOLS ; EXCITED-STATE ; MODEL SYSTEMS
收录类别	SCI
语种	英语
WOS记录号	WOS:000303935700033
公开日期	2012-11-11
内容类型	期刊论文
源URL	[http://ir.qibebt.ac.cn:8080/handle/337004/1260]
专题	青岛生物能源与过程研究所_多相催化转化团队
作者单位	1.Tech Univ Munich, Dept Chem, D-85747 Garching, Germany 2.Univ Texas Austin, Dept Chem & Biochem, Austin, TX 78712 USA 3.Indian Inst Sci, Dept Inorgan & Phys Chem, Bangalore 560012, Karnataka, India 4.Chinese Acad Sci, Qingdao Inst Bioenergy & Bioproc Technol, Qingdao 266101, Peoples R China
推荐引用方式 GB/T 7714	Venkatesan, T. S.,Ramesh, S. G.,Lan, Z.,et al. Theoretical analysis of photoinduced H-atom elimination in thiophenol[J]. JOURNAL OF CHEMICAL PHYSICS,2012,136(17).
APA	Venkatesan, T. S.,Ramesh, S. G.,Lan, Z.,&Domcke, W..(2012).Theoretical analysis of photoinduced H-atom elimination in thiophenol.JOURNAL OF CHEMICAL PHYSICS,136(17).
MLA	Venkatesan, T. S.,et al."Theoretical analysis of photoinduced H-atom elimination in thiophenol".JOURNAL OF CHEMICAL PHYSICS 136.17(2012).