title: Microsolvation effect and hydrogen-bonding pattern of taurine-water TA-(H2O)n (n = 1-3) complexes.
abstract: The microsolvation of taurine (TA) with one, two or three water molecules was investigated by a density functional theory (DFT) approach. Quantum theory of atoms in molecules (QTAIM) analyses were employed to elucidate the hydrogen bond (H-bond) interaction characteristics in TA-(H(2)O)(n) (n = 1-3) complexes. The results showed that the intramolecular H-bond formed between the hydroxyl and the N atom of TA are retained in most TA-(H(2)O)(n) (n = 1-3) complexes, and are strengthened via cooperative effects among multiple H-bonds from n = 1-3. A trend of proton transformation exists from the hydroxyl to the N atom, which finally results in the cleavage of the origin intramolecular H-bond and the formation of a new intramolecular H-bond between the amino and the O atom of TA. Therefore, the most stable TA-(H(2)O)(3) complex becomes a zwitterionic complex rather than a neutral type. A many-body interaction analysis showed that the major contributors to the binding energies for complexes are the two-body energies, while three-body energies and relaxation energies make significant contributions to the binding energies for some complexes, whereas the four-body energies are too small to be significant.
authors.affiliation: Tianjin Key Laboratory of Structure and Performance for Functional Molecules, College of Chemistry, Tianjin Normal University, Tianjin, People's Republic of China.
authors.forename: Yumei
authors.initials: Y
authors.lastname: Dai
authors.forename: Yuhua
authors.initials: Y
authors.lastname: Wang
authors.forename: Zhengguo
authors.initials: Z
authors.lastname: Huang
authors.forename: Hongke
authors.initials: H
authors.lastname: Wang
authors.forename: Lei
authors.initials: L
authors.lastname: Yu
mesh_terms: D006860:Hydrogen Bonding; D008958:Models, Molecular; D015394:Molecular Structure; D011522:Protons; D011789:Quantum Theory; D012996:Solutions / Q000737:chemistry; D013654:Taurine / Q000737:chemistry*; D014867:Water / Q000737:chemistry*
chemical_list: D011522:Protons; D012996:Solutions; D014867:Water; D013654:Taurine