Article ID | Journal | Published Year | Pages | File Type |
---|---|---|---|---|
9591027 | Journal of Molecular Structure: THEOCHEM | 2005 | 7 Pages |
Abstract
A systematic investigation of the proton transfer in the tautomerization of 2-mercaptoimidazole was undertaken. Calculations in aqueous solution were performed using the combined supramolecular/continuum and the direct continuum models, respectively. Complexes containing one and two water molecules around the hydrophilic site of 2-mercaptoimidazole were used for the combined supramolecular/continuum calculation. DFT results predict that the barrier height for non-water-assisted intramolecular proton transfer is very high (175.8Â kJ/mol). Hydrogen bonding between 2-mercaptoimidazole and the water molecule(s) will dramatically lower the barrier by the concerted multiple proton transfer mechanism. The proton transfer process through a eight-member ring formed by 2-mercaptoimidazole and two water molecules is found to be more efficient one and the calculated barrier height is reduced to ca. 72Â kJ/mol.
Keywords
Related Topics
Physical Sciences and Engineering
Chemistry
Physical and Theoretical Chemistry
Authors
Hua-Jie Zhu, Yi Ren, Jie Ren, San-Yan Chu,