Protonation-induced conformational Changes of 2-(N,N-Dimethylamino)ethanethiol.Importance of Strong N-H~+...S and N-H~+...S~- Hydrogen Bonding

摘要

2-(N,N-Dimethylamino)ethanethiol exists in aqueous solution as a cation,zwitterion,or anion in different pH regions.Me_2NH~+EtSH and Me_2nh~+EtS~- assume the gauche conformation around the NC-CS bond,as stabliized by strong intramolecular 1,4-N-H~+...S and 1,4-N-H~+...S~- hydrogen bondings,respectively,while Me_2NEtS~- assumes the trans conformation around the same bond.