Influence of Fluorination on the Conformational Properties and Hydrogen-Bond Acidity of Benzyl Alcohol Derivatives.
Influence of Fluorination on the Conformational Properties and Hydrogen-Bond Acidity of Benzyl Alcohol Derivatives.
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DOI：
10.1002/chem.201501171
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发表时间：
2015-08-03
期刊：
影响因子：
--
通讯作者：
Graton J
中科院分区：
文献类型：
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作者：
Bogdan E;Compain G;Mtashobya L;Le Questel JY;Besseau F;Galland N;Linclau B;Graton J
用红外光谱和量子化学方法（从头算（MP 2）和密度泛函理论（MPWB 1 K））研究了苯甲醇分子的构象和氢键性质.结果表明，邻位取代通常会增加羟基的HB酸性，而邻位取代则会降低羟基的HB酸性。计算分析表明，标题化合物的构象景观的存在下，邻氟原子的强烈影响。基于AIM、NCI和NBO分析的分子内相互作用描述符表明，除了分子内OH⋅F相互作用外，还发生二级CH⋅F和/或CH⋅O相互作用，有助于各种构象的稳定，并影响醇基的整体HB性质。苯甲醇HB捐助能力的趋势是适当的描述了基于静电势的描述符计算在MPWB 1 K/6-31+G（d，p）的理论水平，提供溶剂化效应考虑到这些灵活的HB捐助者。
The effect of fluorination on the conformational and hydrogen-bond (HB)-donating properties of a series of benzyl alcohols has been investigated experimentally by IR spectroscopy and theoretically with quantum chemical methods (ab initio (MP2) and DFT (MPWB1K)). It was found that o-fluorination generally resulted in an increase in the HB acidity of the hydroxyl group, whereas a decrease was observed upon o,o′-difluorination. Computational analysis showed that the conformational landscapes of the title compounds are strongly influenced by the presence of o-fluorine atoms. Intramolecular interaction descriptors based on AIM, NCI and NBO analyses reveal that, in addition to an intramolecular OH⋅⋅⋅F interaction, secondary CH⋅⋅⋅F and/or CH⋅⋅⋅O interactions also occur, contributing to the stabilisation of the various conformations, and influencing the overall HB properties of the alcohol group. The benzyl alcohol HB-donating capacity trends are properly described by an electrostatic potential based descriptor calculated at the MPWB1K/6-31+G(d,p) level of theory, provided solvation effects are taken into account for these flexible HB donors.