Prediction models for the Abraham hydrogen bond donor strength: comparison of semi‐empirical,ab initio,and DFT methods |
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Authors: | Johannes A. H. Schwöbel Ralf‐Uwe Ebert Ralph Kühne Gerrit Schüürmann |
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Affiliation: | 1. UFZ Department of Ecological Chemistry, Helmholtz Centre for Environmental Research, Permoserstr. 15, 04318 Leipzig, Germany;2. Institute for Organic Chemistry, Technical University Bergakademie Freiberg, Leipziger Strasse 29, 09596 Freiberg, Germany |
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Abstract: | Hydrogen bonding has a great impact on the partitioning of organic compounds in biological and environmental systems as well as on the shape and functionality of macromolecules. Electronic characteristics of single molecules, localized at the H‐bond (HB) donor site, are able to estimate the donor strength in terms of the Abraham parameter A. The quantum chemically calculated properties encode electrostatic, polarizability, and charge‐transfer contributions to hydrogen bonding. A recently introduced respective approach is extended to amides with more than one H atom per donor site, and adapted to the semi‐empirical AM1 scheme. For 451 organic compounds covering acidic ? CH, ? NH? , and ? OH groups, the squared correlation coefficient is 0.95 for the Hartree–Fock and density functional theory (B3LYP) level of calculation, and 0.84 with AM1. The discussion includes separate analyses for weak, moderate, and strong HB donors, a comparison with the performance of increment methods, and opportunities for consensus modeling through the combined use of increment and quantum chemical methods. Copyright © 2011 John Wiley & Sons, Ltd. |
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Keywords: | Abraham parameter AM1 B3LYP HF hydrogen bonding H‐bond acidity H‐bond donor strength linear solvation energy relationship local molecular reactivity LSER quantum chemical |
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