Study on the Production and the Reaction Mechanism of Unstable Molecules produced by the Pyrolysis and Photolysis

观察了含N-氯分子及其热解产物的红外光谱。根据从头算的计算结果，对光谱进行了分析。利用过渡态的结构和能量信息，从实验和理论上探讨了NH_2Cl的热解机理。(1)在中红外波段测量了NH_2Cl的高分辨光谱。氨基剪切层的反转分裂约为0.2 cm^~(-1)。这是除摆动带外首次观测到的反转分裂现象。(2)观察到二烷胺的热解反应有两个分支：R_1(R_2)nCL(R_1，R_2：C_2H_5，C_3H_7)，一个是脱氯化氢反应，另一个是C-N反应。分支是依赖于温度的。在较低温度下进行脱氯化氢反应生成亚胺类化合物。(3)采用MOPAC-PM3方法计算了与胺类化合物热解相关的分子和过渡态的相对稳定性。结果被用来鉴定和预测反应产物。对分子内氢转移、环转移和脱氢等热解机理进行了详细的研究。

Infrared spectra of the N-Cl containing molecules and their pyrolytic products have been observed. The Spectra were analyzed guided by the results of ab initio MO calculations. The pyrolytic mechanism were considered experiment-ally and also theoretically using the information of the structures and energ-ies of the transition states.(1) High resolution spectra of NH_2Cl were measured in the mid-infrared region. The amino scissorring level has the inversion splitting of about 0.2cm^<-1>. This is the first of observation of the inversion splitting except the wagging band. The amino twisting band was observed, and nu_0 was determined to be 1169cm^<-1>.(2) There have been observed two branchings of the pyrolysis reaction of dialkylamines, R_1(R_2)NCl (R_1, R_2 : C_2H_5, C_3H_7), one is the dehydrochlorination, and the other is C-N cession. The branching is temperature-dependent. and at lower temperature proceeds the dehydrochlorination to give imines.(3) MOPAC-PM3 method was applied to calculate the relative stabilities of the molecules and transition states related to the pyrolysis of amines. The results were used to identify and predict the reaction products. The pyrotitic mechanism including the intramolecular hydrogen transfer, ring cession, and dehydrogen has been invesigated in detail.