限域1F-分子筛Asn分子的手性转变机制

基于密度泛函理论,在ONIOM(CAM-B3LYP/6-31G(d,p):UFF)基组水平上,研究1F-分子筛限域条件下的天冬酰胺(Asn)分子手性转变过程,寻找天冬酰胺分子手性反应过程中各过渡态与中间体的极值点结构,绘制1F-分子筛限域条件下完整的天冬酰胺分子手性转变路径反应势能面,并分析各极值点的几何和电子结构特性.结果表明:1F-分子筛限域条件下S型天冬酰胺分子手性C上的H原子以羧基上的O原子为桥梁,转移至手性C原子的另一侧,实现从S型到R型天冬酰胺分子的手性转变;最大的反应能垒为321.361 2kJ/mol,来源于第二个过渡态TS_1-S-Asn@1F-MOL.

Chiral Transition Mechanism of Asparagine Molecule Confined in 1F-Molecular Sieve

Based on the density functional theory, we investigated the chiral transition process of the asparagine molecule in 1F-MOL at the level of ONIOM (CAM-B3LYP/6-31G(-d,p-): UFF) basis set. We drew a complete chiral transition path reaction potential energy surface by finding thestructures of the extreme value points including the transition states and intermediates, and analyzed the geometric and electronic structure properties of extreme value points. The results show that the hy drogen atom on the chiral carbon atom of S asparagine molecule can transferto the other side of the carbon atom via the oxygen atoms of carboxyl group as a bridge, and achieve the chiral transition of asparagine molecule from S type to R type. The maximum reaction energy barrier is 321361 2 kJ/mol, which comes from the second transition state TS₁-R-Asn@1F MOL.