Cooperative enhancement of water binding to crownophane by multiple hydrogen bonds: Analysis by high level ab initio calculations

Citation
S. Tsuzuki et al., Cooperative enhancement of water binding to crownophane by multiple hydrogen bonds: Analysis by high level ab initio calculations, J AM CHEM S, 123(18), 2001, pp. 4255-4258
Citations number
44
Language
INGLESE
art.tipo
Article
Categorie Soggetti
Chemistry & Analysis",Chemistry
Journal title
JOURNAL OF THE AMERICAN CHEMICAL SOCIETY
ISSN journal
0002-7863 → ACNP
Volume
123
Issue
18
Year of publication
2001
Pages
4255 - 4258
Database
ISI
SICI code
0002-7863(20010509)123:18<4255:CEOWBT>2.0.ZU;2-P
Abstract
The intermolecular interaction energy of the model system of the water-crow nophane complex was analyzed. The water molecule has four hydrogen bonds, w ith the two hydrogen-donating phenolic hydroxy groups and two hydrogen-acce pting oxygen atoms of the poly-oxyethylene chain of the crownophane in the complex. The MP2/6-311G(2d,2p) level calculations of the model system of th e complex (hydrogen donating unit + hydrogen accepting unit + water) indica te that the binding energy of the water is 21.85 kcal/mol and that the hydr ogen bond cooperativity increases the binding energy as much as 3.67 kcal/m ol. The calculated interaction energies depend on the basis set, while the basis set dependence of the cooperative increment is negligible. Most of th e cooperative increment is covered by the HF level calculation, which sugge sts that the major source of the hydrogen bond cooperativity in this system has its origin in induction. The BLYP/6-311G** and PW91/6-311G** level int eraction energies of the model system are close to the MP2/6-311G** interac tion energies, which suggests that the DFT calculations with these function als are useful methods to evaluated the interactions of hydrogen bonded sys tems.