Theoretical determination of molecular structure and conformation. 6. The Criegee intermediate. Evidence for a stabilization of its syn form by alkyl substituents
Theoretical determination of molecular structure and conformation. 6. The Criegee intermediate. Evidence for a stabilization of its syn form by alkyl substituents
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分子结构和构象的理论测定。
DOI：
10.1021/ja00518a013
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发表时间：
1979
影响因子：
15
通讯作者：
D. Cremer
中科院分区：
文献类型：
--
作者：
D. Cremer
利用d型极化函数增强的分裂价基，对臭氧分解反应的所谓Criegee中间体过氧亚甲基进行了瑞利-薛定谔- mqler - plesset （RSMP）微扰计算。精确的平衡结构的弯曲，线性和垂直分子及其环异构体，二氧环己烷，已经确定。这些结构的旋转势垒和反转势垒分别为32 kcal/mol和41 kcal/mol。甲基取代增强了这些屏障。因此，在液相臭氧分解中必须排除同步和反烷基过氧亚甲基的平衡。在非极性溶剂中，甲基过氧亚甲基的顺式比反式稳定3-4千卡/摩尔。
Rayleigh-Schrodinger-Mqller-Plesset (RSMP) perturbation calculations using a split-valence basis augmented by d-type polarization functions have been carried out on peroxymethylene, the so-called Criegee intermediate of the ozonolysis reaction. Accurate equilibrium structures for the bent, linear, and perpendicular molecule as well as its cyclic isomer, dioxirane, have been determined. With these structures, the barriers to rotation and inversion have been found to be 32 and 41 kcal/mol, respectively. Methyl substitution enhances these barriers. Thus, an equilibration of syn and anti alkylperoxymethylenes in solution-phase ozonolysis has to be excluded. In nonpolar solvents, the syn form of methylperoxymethylene is more stable by 3-4 kcal/mol than the anti form.