Investigations of the hydrogen bond in the crystals of tropolone and thiotropolone via car-parrinello and path integral molecular dynamics
© 2018 Wiley Periodicals, Inc.
| Veröffentlicht in: | Journal of computational chemistry. - 1984. - 40(2019), 4 vom: 05. Feb., Seite 671-687 |
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| Format: | Online-Aufsatz |
| Sprache: | English |
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2019
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| Zugriff auf das übergeordnete Werk: | Journal of computational chemistry |
| Schlagworte: | Journal Article fast proton transfer low-barrier hydrogen bond resonance-assisted hydrogen bond thiotropolone tropolone |
| Zusammenfassung: | © 2018 Wiley Periodicals, Inc. Car-Parrinello and path integrals molecular dynamics (CPMD and PIMD) simulations were carried out for the 10π-electron aromatic systems: 2-hydroxy-2,4,6-cycloheptatrien-1-one, commonly known as Tropolone (I) and 2-hydroxy-2,4,6-cycloheptatriene-1-thione, called Thiotropolone (II) in vacuo and in the solid state. The extremely fast proton transfer (FPT) and "prototropy" tautomerism in the keto-enol (thione-enethiol) systems have been analyzed on the basis of CPMD and PIMD methods level. Comparisons of two-dimensional (2D) free-energy landscapes of reaction coordinate δ-parameter and RO…O or RO…S distances shows that the OH… tautomer to be more favorable in the Thiotropolone. The hydrogen between the oxygen and the sulfur atoms adopts a starkly asymmetrical position in the double potential well. The values of the energy barriers for the FPT were calculated and suggested a strong hydrogen bond with low barrier for FPT mechanism. These studies and the 2D average index of π-delocalization 〈λ〉 landscape of time evolutions of RO1…O2 and RC7O2 or RC7S1 distances for the both crystals indicate that hydrogen bonds in the crystals of Tropolone (I) and Thiotropolone (II) have characteristic properties for the type of bonding model resonance-assisted hydrogen bonds and also low-barrier hydrogen bonds. In the crystal of the Thiotropolone (II), we found the hydrogen bond OH…S existing without the equilibrium of the two tautomers whereas in the crystal of the Tropolone (I) has been confirmed the hydrogen bond OH…O existing with the equilibrium of the two tautomers. It was also found the significant differences in frequency, speed, and the image of the FPT in the studied crystals. © 2018 Wiley Periodicals, Inc |
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| Beschreibung: | Date Revised 20.11.2019 published: Print-Electronic Citation Status PubMed-not-MEDLINE |
| ISSN: | 1096-987X |
| DOI: | 10.1002/jcc.25753 |