Activation and Thermodynamic Parameter Study of the Heteronuclear C鈺怬路路路H鈥揘 Hydrogen Bonding of Diphenylurethane Isomeric Structures by FT-IR Spectroscopy Using the Regularized Inversion of an Eigenva

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• 作者：Nicolas Spegazzini ; Heinz W. Siesler ; Yukihiro Ozaki
• 刊名：The Journal of Physical Chemistry A
• 出版年：2012
• 出版时间：August 2, 2012
• 年：2012
• 卷：116
• 期：30
• 页码：7797-7808
• 全文大小：659K
• 年卷期：v.116,no.30(August 2, 2012)
• ISSN：1520-5215

文摘

The doublet of the 谓(C鈺怬) carbonyl band in isomeric urethane systems has been extensively discussed in qualitative terms on the basis of FT-IR spectroscopy of the macromolecular structures. Recently, a reaction extent model was proposed as an inverse kinetic problem for the synthesis of diphenylurethane for which hydrogen-bonded and non-hydrogen-bonded C鈺怬 functionalities were identified. In this article, the heteronuclear C鈺怬路路路H鈥揘 hydrogen bonding in the isomeric structure of diphenylurethane synthesized from phenylisocyanate and phenol was investigated via FT-IR spectroscopy, using a methodology of regularization for the inverse reaction extent model through an eigenvalue problem. The kinetic and thermodynamic parameters of this system were derived directly from the spectroscopic data. The activation and thermodynamic parameters of the isomeric structures of diphenylurethane linked through a hydrogen bonding equilibrium were studied. The study determined the enthalpy (螖H = 15.25 kJ/mol), entropy (T螖S = 14.61 kJ/mol), and free energy (螖G = 0.6 kJ/mol) of heteronuclear C鈺怬路路路H鈥揘 hydrogen bonding by FT-IR spectroscopy through direct calculation from the differences in the kinetic parameters (未螖^{鈥?/sup>H, 鈥?i>T未螖鈥?/sup>S, and 未螖鈥?/sup>G) at equilibrium in the chemical reaction system. The parameters obtained in this study may contribute toward a better understanding of the properties of, and interactions in, supramolecular systems, such as the switching behavior of hydrogen bonding.}