Guo Wentao, Kong Wang-Yeuk, Tantillo Dean J
Department of Chemistry, Univeristy of California Davis USA
Chem Sci. 2024 Aug 27;15(38):15577-87. doi: 10.1039/d4sc04829f.
Density functional theory computations were used to model the formation and rearrangement of the barbaralyl cation (CH ). Two highly delocalized minima were located for CH , one of symmetry and the other of symmetry, with the former having lower energy. Quantum chemistry-based NMR predictions affirm that the lower energy structure is the best match with experimental spectra. Partial scrambling was found to proceed through a symmetric transition structure associated with a barrier of only 2.3 kcal mol. The full scrambling was found to involve a symmetric transition structure associated with a 5.0 kcal mol barrier. molecular dynamics simulations initiated from the CH structure revealed its connection to six minima, due to the six-fold symmetry of the potential energy surface. The effects of tunneling and boron substitution on this complex reaction network were also examined.
密度泛函理论计算用于模拟巴巴罗亚阳离子（CH ）的形成和重排。为CH 找到了两个高度离域的极小值，一个具有 对称性，另一个具有 对称性，前者能量较低。基于量子化学的核磁共振预测证实，能量较低的结构与实验光谱最匹配。发现部分重排通过一个仅具有 2.3 kcal/mol 势垒的 对称过渡结构进行。发现完全重排涉及一个具有 5.0 kcal/mol 势垒的 对称过渡结构。从 CH 结构开始的分子动力学模拟揭示了由于势能面的六重对称性，它与六个极小值的联系。还研究了隧穿和硼取代对这个复杂反应网络的影响。
