Abstract:

We investigated chiral transition mechanism of α-Ala molecule under complex environment of singlewalled carbon nanotubes and water based on amidogen as H transfer bridge by using the method of quantum chemistry ONIOM. The results show that there are two shift reaction channels a and b based on amidogen as a bridge of hydrogen transfer process in chiral transformation. The channel a is the most advantage way. Armchair SWCNT/water complex environment provide a preferable catalytic effect for hydrogen transfer reaction. Under the confined environment of SWCNT(8,8), compared with the primary reaction, the rate determining step energy barrier drops from 266.1 kJ/mol of naked reaction to 117.8 kJ/mol using chain of three water molecules. Thus the SWCNT (8,8)/water complex can used as an ideal nano reactor of implementation α-Ala chiral shift, and α-Ala molecule will also make this optical isomerism reacion reality in a similar nano environment in organisms.

Key words: chiral transition, α-alanine, carbon nanotube, ONIOM method, density functional theory, transition state, perturbation theory