Abbasoglu Rza
Department of Chemistry, Karadeniz Technical University, 61080, Trabzon, Turkey.
J Mol Model. 2006 Sep;12(6):991-5. doi: 10.1007/s00894-006-0113-3. Epub 2006 May 6.
The electronic and geometric structures of tetracyclo[5.3.0.0(2,6).0(3,10)]deca-4,8-diene (hypostrophene) have been investigated by ab initio and DFT/B3LYP methods using the 6-31G* and 6-311G* basis sets. The double bonds of hypostrophene are endo-pyramidalized. The cationic intermediates and products formed in the addition reaction have been investigated using the HF/6-311G*, HF/6-311G**, and B3LYP/6-311G* methods. The bridged bromonium cation was more stable than the U-type cation. Considering that the bridged cation does not isomerize to the less stable U-type cation, it is not possible for the U-type product to be obtained in the reaction. The bridged bromonium cation transformed into the more stable N-type cation and the N-type product was obtained via this cation. The thermodynamic stability of the exo, exo and exo, endo isomers of the N-type dibromide molecule were almost identical. The N-type product was 16.6 kcal mol(-1) more stable than the U-type product.
采用6-31G和6-311G基组，通过从头算和DFT/B3LYP方法研究了四环[5.3.0.0(2,6).0(3,10)]癸-4,8-二烯（次扭转烯）的电子结构和几何结构。次扭转烯的双键呈内锥化。使用HF/6-311G*、HF/6-311G*和B3LYP/6-311G方法研究了加成反应中形成的阳离子中间体和产物。桥连溴鎓阳离子比U型阳离子更稳定。考虑到桥连阳离子不会异构化为较不稳定的U型阳离子，因此在反应中不可能得到U型产物。桥连溴鎓阳离子转化为更稳定的N型阳离子，并通过该阳离子得到N型产物。N型二溴化物分子的外型、外型和外型、内型异构体的热力学稳定性几乎相同。N型产物比U型产物稳定16.6 kcal mol(-1)。
