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本文用Morokuma提出的数值方案,基于SCF MO ab initio(STO-3G),求得了乙叉到乙炔重排反应的内禀反应坐标IRC(Fukui提出的与坐标系无关的反应途径),并对反应过程中几何构型的改变进行了讨论,在用MINDD/3方法对诚反应进行研究时,发现反应过程中有其它中间体存在,本文也对这种不正确的结果进行了讨论。本文优化得到的反应物、产物和过渡态几何构型与更精确的理论方法所得的结果定性相符,用单行列式和CID(考虑所有双激发组态的组态相互作用)所得该反应的位垒分别为123.85和95.81 kJmol~(-1),也与更精确方法得到的值相符;本文还得到了该反应的过渡态的振动频率和正则振动模式。
In this paper, the numerical solution proposed by Morokuma is based on SCF MO ab initio (STO-3G). The intrinsic reaction coordinate (IRC) of ethylidene acetylene rearrangement reaction is obtained (Fukui’s unrelated coordinate reaction) The change of geometric configuration during the process is discussed. In the case of the MINDD / 3 method, some other intermediates are found during the reaction. This incorrect result is also discussed in this paper. The optimized reactants, products, and transition geometries obtained in this work agree qualitatively with the results obtained from the more accurate theoretical methods. Using the single determinant and the CID (considering the configuration interactions of all double-excited configurations) the resulting position of the reaction The barriers are 123.85 and 95.81 kJmol -1, respectively, which are in good agreement with those obtained by a more accurate method. The vibration frequencies and regular vibrational modes of the transition state are also obtained.