Mechanism of Hydrogen-Bond Array Isomerization in Tetrahydroxycalix[4]arene and Tetrahydroxythiacalix[4]arene
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- 作者：Ji
//pubs.acs.org/images/entities/rcaron.gif" border="0">í ; Matou
- 刊名：Journal of Physical Chemistry A
- 出版年：2008
- 出版时间：February 7, 2008
- 年：2008
- 卷：112
- 期：5
- 页码：1076 - 1084
- 全文大小：573K
- 年卷期：v.112,no.5(February 7, 2008)
- ISSN：1520-5215
文摘
Possible rearrangement mechanisms of hydrogen-bond arrays formed at the lower rim of tetrahydroxycalix[4]arene and tetrahydroxythiacalix[4]arene were studied by means of density functional theory and the resolutionidentity approximation modification of M
gif">ller-Plesset perturbation theory (RI-MP2). Influence of solvent toheight of energy barriers was quantified by use of the conductorlike screening model (COSMO) of implicitsolvent (chloroform). Generally, two types of mechanisms were investigated. The first is represented by asynchronous single-step jump of all four hydroxyl protons. Pathways of the second mechanism include therotation of one or more hydroxyl groups around the CAr-O bond. Theoretical results, in agreement withrecently published experimental data (Lang et al. J. Chem. Phys. 2005, 122, 044056), prefer a jump mechanismfor the methylene-bridged calix[4]arene. Concerning the thiacalix[4]arene, results obtained by COSMO aswell as RI-MP2 calculations show that the rotational mechanism is very competitive and it could even bemore favorable.
gif">ller-Plesset perturbation theory (RI-MP2). Influence of solvent toheight of energy barriers was quantified by use of the conductorlike screening model (COSMO) of implicitsolvent (chloroform). Generally, two types of mechanisms were investigated. The first is represented by asynchronous single-step jump of all four hydroxyl protons. Pathways of the second mechanism include therotation of one or more hydroxyl groups around the CAr-O bond. Theoretical results, in agreement withrecently published experimental data (Lang et al. J. Chem. Phys. 2005, 122, 044056), prefer a jump mechanismfor the methylene-bridged calix[4]arene. Concerning the thiacalix[4]arene, results obtained by COSMO aswell as RI-MP2 calculations show that the rotational mechanism is very competitive and it could even bemore favorable.