Abstract:

Using density functional theory at the level of B3LYP/6-311+G(2df), we investigated the chiral transition process of the nonrestricted area monomer asparagine molecule. We drawed a complete asparagine molecule chiral transition path reaction potential energy surface by finding stuctures of the extreme value points of recation process of transition states and intermediates, and analyzed the geometric and electronic structure characteristics of extreme value points. The results show that the hydrogen atom on the chiral carbon atom of Sasparagine molecule can transfer to the other side of the carbon atom via the oxygen atoms of carboxyl atoms as a bridge, and achieve the chiral transition of asparagine molecule from S-type to R-type. On this path there are four intermediate and five transition states. The maximum reaction energy barrier is 316.372 8 kJ/mol, which comes from the fourth transition states TS-_2-R-Asn.

Key words: chirality, asparagine, transition state, transition process, potential energy surface