Hartree-Fock and Density Functional Theory Study of -Cyclodextrin Conformers
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- 作者：Veró ; nica Jimé ; nez ; Joel B. Alderete
- 刊名：Journal of Physical Chemistry A
- 出版年：2008
- 出版时间：January 31, 2008
- 年：2008
- 卷：112
- 期：4
- 页码：678 - 685
- 全文大小：284K
- 年卷期：v.112,no.4(January 31, 2008)
- ISSN：1520-5215
文摘
Herein, we report the geometry optimization of four conformers of 
-cyclodextrin (-CD) by means of PM3,HF/STO-3G, HF/3-21G, HF/6-31G(d), B3LYP/6-31G(d), and X3LYP/6-31G(d) calculations. The analysisof several geometrical parameters indicates that all conformers possess bond lengths, angles, and dihedralsthat agree fairly well with the crystalline structure of -CD. However, only three of them (1-3) resemble thepolar character of CDs and show intramolecular hydrogen-bonding patterns that agree with experimentalNMR data. Among them, conformer 3 appears to be the most stable species both in the gas phase and insolution; therefore, it is expected to be the most suitable representative structure for -CD conformation. Thepurpose of selecting such a species is to identify an appropriate structure to be employed as a starting pointfor reliable computational studies on complexation phenomena. Our results indicate that the choice of aparticular -CD conformer should affect the results of ab initio computational studies on the inclusioncomplexation with this cyclodextrin since both the direction and the magnitude of the dipole moment dependstrongly on the conformation of -CD.
-cyclodextrin (-CD) by means of PM3,HF/STO-3G, HF/3-21G, HF/6-31G(d), B3LYP/6-31G(d), and X3LYP/6-31G(d) calculations. The analysisof several geometrical parameters indicates that all conformers possess bond lengths, angles, and dihedralsthat agree fairly well with the crystalline structure of -CD. However, only three of them (1-3) resemble thepolar character of CDs and show intramolecular hydrogen-bonding patterns that agree with experimentalNMR data. Among them, conformer 3 appears to be the most stable species both in the gas phase and insolution; therefore, it is expected to be the most suitable representative structure for -CD conformation. Thepurpose of selecting such a species is to identify an appropriate structure to be employed as a starting pointfor reliable computational studies on complexation phenomena. Our results indicate that the choice of aparticular -CD conformer should affect the results of ab initio computational studies on the inclusioncomplexation with this cyclodextrin since both the direction and the magnitude of the dipole moment dependstrongly on the conformation of -CD.