He（2~3s）与CH_nCl_（4－n）（n＝1～4）在束－气条件下的传能解离激发反应

Dissociation Excitation of CH_nCl_(4-n)(n=1-4)by the Energy Transfer of He(2￣3 s)Under a Beam-Gas Condition

在束－气条件下，通过检测反应产物的化学发光光谱，研究了亚稳态Ｈｅ（２~３ｓ）原子与甲烷、氯代甲烷（ＣＨ_ｎＣｌ_（４－ｎ），ｎ＝１～３）反应中的解离激发动力学过程．观察到反应的主要激发态碎片ＣＨ（Ａ~２Δ）、ＣＨ（Ｂ~２Σ^（－））、ＣＨ（Ｃ~２Σ~＋）、Ｈ和ＣＣｌ（Ａ~２Δ），用参比反应测定了发光碎片的形成速率常数。对ＣＨ（Ａ，Ｂ）光谱的计算机模拟获得了ＣＨ（Ａ~２Δ，ｖ′＝０～２）和ＣＨ（Ｂ，ｖ′＝０）的振转分布。该反应的可资用能绝大部分转移成产物的平动能，且Ｈｅ（２~３ｓ）与甲烷及氯代甲烷反应形成ＣＨ（Ａ~２Δ，ｖ′＝０）的转动分布不同，前者为单Ｂｏｌｔｚｍａｎｎ分布，后者则在低转动能级上转动温度比高转动态低，近似可用双Ｂｏｌｔｚｍａｎｎ分布描述，对上述反应机理进行了讨论。

The kinetic processes of dissociation excitation of CH_nCl_(4-n)(n=1-4)colliding with He(2￣3s)were studied by observing the emissions of products。The formation rate constants of CH(A),CH(B),CH(C),H and CCI(A)from He(2￣3s)/CH_nCl_(4-n)(n=1-4)reaction were determined by using the reference reaction method.The rovibrational distribution of CH(A￣2Δ,v′=0-2)and CH(B￣2Σ,v′=0)was also obtained by a computer simulation of CH(A-X,B-X)emission. The experimental results showed that the rotational distribution of CH(A￣2Δ,v′=0)from He(2￣3s)and CH_nCl_(4-n)(n=1-3)was expressed as the double Boltzmann temperature,which is different from that of He(2￣3s)/CH_4.It is also noted that the major available energies of the reactions are deposited into relative translational energy of products.The mechanism of the reactions He(2￣3s)with CH_nCl_(4-n)has been suggested.