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在气束条件下 ,利用 4 83.2nm的激光 (3+ 1)共振增强多光子电离 (REMPI)CS2 分子以产生CS2 +离子源 ,用另一束可调谐激光在 4 2 4～ 4 82nm内 ,通过对CS2 +( X2 Πg) (1+ 1)双光子共振解离产生的碎片离子激发谱的探测 ,来获取CS2 +的光解离动力学信息。光解离碎片S+的激发谱(PHOFEX)可归属为CS2 +( A2 Πu,3/2 (v′ =0～ 4 ,v′ =v1′ + (1/ 2 )v2 ′)← X2 Πg ,3/2 (0 ,0 ,0 ) )和 ( A2 Πu,1/2 (v′ =0～ 4 )← X2 Πg ,1/2 (0 ,0 ,0 ) )的跃迁。对CS2 +光解离动力学的研究表明 ,其产生S+的通道为 :(i)CS2 +吸收一个光子从基态 X2 Πg 共振激发至 A2 Πu 态 ,(ii)已布居的 A2 Πu 态的振动能级和 X2 Πg 态的高振动能级产生耦合 ,(iii)吸收第二个光子从上述耦合的振动能级进一步激发至 B2 Σu+态 ,再通过 B2 Σu+态与4 Σ- 态间的自旋 -轨道相互作用 ,经由4 Σ- 排斥态解离产生S++CS。
Under the condition of gas beam, the multi-photon ionization (REMPI) CS2 molecule is excited by the 4 83.2 nm laser (3+ 1) resonance to generate the CS2 + ion source. With another tunable laser beam in 4 2 4 ~ 4 82 nm, The photolysis kinetic information of CS2 + was obtained by detecting the fragment ion excitation spectrum generated by two-photon resonance dissociation of CS2 + (X2 Πg) (1+ 1). The excitation spectrum (PHOFEX) of photodissociation fragment S + can be attributed to CS2 + (A2 Πu, 3/2 (v ’= 0 ~ 4, v’ = v1 ’+ (1/2) v2’) ← X2Πg, 3 / 2 (0, 0, 0)) and (A2 Πu, ½ (v ’= 0~4) ← X2 Πg, 1/2 (0, 0, 0)). Studies on photodissociation dynamics of CS2 + show that the channel for generating S + is: (i) CS2 + absorbs a photon excited from the ground state X2Πg to the A2Πu state, (ii) the vibration of the A2 Πu state inhabited (Iii) absorption of a second photon from the coupled vibrational level further excited to the B2Σu + state, and then through B2Σu + state and 4Σ-state spin between - Orbit interactions, resulting in S ++ CS dissociation via 4Σ-repulsion states.