Ab Initio QM/MM-MC Study on Hydrogen Transfer of Glycine Tautomerization in Aqueous Solution: Helmholtz Energy Changes along Water-mediated and Direct Processes

作者：Miyamoto Hidenori; Aida Misako^*

来源：Chemistry Letters, 2013, 42(6): 598-600.

DOI：10.1246/cl.130126

Helmholtz free-energy changes in aqueous solution along two paths of glycine tautomerization were investigated by using an ab initio QM/MM-MC method with the thermodynamic perturbation theory. Glycine and one water molecule were treated at the quantum mechanics (QM) level of MP2/6-31G(d); these were surrounded by 100 water molecules at the molecular mechanics (MM) level of TIP3P. AIM (atoms-in-molecules) analysis showed that the transfer of two hydrogen atoms occurs simultaneously along the water-mediated path. The free-energy barrier height of this path in aqueous solution was higher than that of the direct path.

• 出版日期2013-6-5