Heteropentámeros (etanol)4-agua: estudio estructural y termodinámico

Mejía, Sol M.; Orrego, Juán F.; Espinal, Juan F.; Mondragón, Fanor

doi:10.1590/s0100-40422010000400018

Cited by 2 publications

(4 citation statements)

References 21 publications

(42 reference statements)

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“…In the case of (ethanol) n -water clusters (with n varying from 1 to 4), where the geometries were optimised at the B3LYP/ 6-31+G(d) level, the C-HÁ Á ÁO interactions are not as strong as the O-HÁ Á ÁO interactions. [20][21][22] However, this is not the case for the (ethanol) 3 -water heterotetramer shown in Fig. 3b, where the strongest interaction is a C-HÁ Á ÁO w HB (see b5 in Fig.…”

Section: Bond Critical Points Distributionmentioning

confidence: 93%

“…In addition, it has been found that the influence of internal ethanol geometry on the geometry and energy of (ethanol) n -water clusters (n = 2, 3 or 4) is insignificant. [20][21][22] However, in a future study it would be interesting to include the two gauche conformers under the hypothesis that their inclusion would not lead to considerable changes in the present results.…”

Section: Computational Details 21 Simulationmentioning

confidence: 96%

“…For example, electronic structure studies showed the formation of C-HÁ Á ÁO HBs between water and ethanol, in clusters as large as four ethanol molecules and one water molecule. [20][21][22] Experimental studies of clusters of isolated (ethanol) n -water only cover the cases of n = 1 and n = 2, [23][24][25] showing that (ethanol) 2 -water adopts a cyclic geometry with all molecules acting as proton donors as well as proton acceptors in three O-HÁ Á ÁO HBs. This result confirms a computational prediction 22 where this cyclic geometry is the most stable amongst the six geometric patterns that were studied.…”

Section: Introductionmentioning

confidence: 99%

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The dynamic behavior of a liquid ethanol–water mixture: a perspective from quantum chemical topology

Mejía

Mills

Shaik

et al. 2011

Phys. Chem. Chem. Phys.

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Quantum Chemical Topology (QCT) is used to reveal the dynamics of atom-atom interactions in a liquid. A molecular dynamics simulation was carried out on an ethanol-water liquid mixture at its azeotropic concentration (X(ethanol)=0.899), using high-rank multipolar electrostatics. A thousand (ethanol)(9)-water heterodecamers, respecting the water-ethanol ratio of the azeotropic mixture, were extracted from the simulation. Ab initio electron densities were computed at the B3LYP/6-31+G(d) level for these molecular clusters. A video shows the dynamical behavior of a pattern of bond critical points and atomic interaction lines, fluctuating over 1 ns. A bond critical point distribution revealed the fluctuating behavior of water and ethanol molecules in terms of O-H···O, C-H···O and H···H interactions. Interestingly, the water molecule formed one to six C-H···O and one to four O-H···O interactions as a proton acceptor. We found that the more localized a dynamical bond critical point distribution, the higher the average electron density at its bond critical points. The formation of multiple C-H···O interactions affected the shape of the oxygen basin of the water molecule, which is shown in three dimensions. The hydrogen atoms of water strongly preferred to form H···H interactions with ethanol's alkyl hydrogen atoms over its hydroxyl hydrogen.

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Section: Bond Critical Points Distributionmentioning

confidence: 93%

Section: Computational Details 21 Simulationmentioning

confidence: 96%

Section: Introductionmentioning

confidence: 99%

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The dynamic behavior of a liquid ethanol–water mixture: a perspective from quantum chemical topology

Mejía

Mills

Shaik

et al. 2011

Phys. Chem. Chem. Phys.

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“…Así, se reportan estudios computacionales, donde se describe que las interacciones que típicamente ocurren en estos sistemas son debidas a enlaces de hidrógeno (Mejía et al, 2007(Mejía et al, , 2010. Estas interacciones intermoleculares son la base para explicar la formación de clústeres (David et al, 2009) y su influencia sobre las propiedades macroscópicas mensurables para estas mezclas; razón por la cual las mezclas alcohol/agua interactúan simultáneamente formando enlaces de hidrógeno primarios y secundarios (Oliveira y Vasconcellos, 2006).…”

Section: Introductionunclassified

Energías de Interacción y Geometrías de Equilibrio para Aglomeraciones de 1,2-propanodiol con 3, 4, 5 y 6 Moléculas de Agua

López¹,

Carriazo

2011

Inf. tecnol.

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ResumenSe reportan las geometrías de equilibrio y energías de interacción de aglomeraciones (clusters) formadas por los sistemas 1,2-propanodiol con 3, 4, 5 y 6 moléculas de agua. Esto con el fin de avanzar en la comprensión de las interacciones que predominan a nivel molecular en compuestos tipo dioles alifáticos con agua. Las aglomeraciones fueron generadas estocásticamente, seleccionadas mediante una prueba de aceptación metrópolis modificado implementado en el programa Recocido Simulado (Simulated Annealing) con Energía Cuántica y optimizados con el nivel de teoría B3LYP/6-31G(d). Las diferentes configuraciones generadas se caracterizaron por la formación preferencial de geometrías cíclicas. En estas geometrías, los enlaces de hidrógeno primario jugaron un rol fundamental en la estabilidad y probabilidad de existencia de estos agregados moleculares. Palabras clave: energías de interacción, clúster, enlace de hidrógeno, 1,2-propanodiol Interaction Energies and Equilibrium Geometries for Clusters 1,2-propanediol with 3, 4, 5 and 6 Water Molecules AbstractThe equilibrium geometries and interaction energies in clusters of 1,2-propanediol with 3,4,5 and 6 water molecules were evaluated. This was done to better comprehend the predominant interactions existing at molecular level in aliphatic diols with water. The clusters were stochastically generated and selected by using a modified metropolis acceptance test implemented in the Simulated Annealing program with Quantum Energy software. The geometry of these systems was optimized by B3LYP/6-31G(d) calculations. The different generated configurations were characterized by the preferential formation of cyclic geometries. In these geometries, the primary hydrogen bonds have a fundamental role on the stability and probability of existence of these molecular aggregates.

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Heteropentámeros (etanol)4-agua: estudio estructural y termodinámico

Cited by 2 publications

References 21 publications

The dynamic behavior of a liquid ethanol–water mixture: a perspective from quantum chemical topology

The dynamic behavior of a liquid ethanol–water mixture: a perspective from quantum chemical topology

Energías de Interacción y Geometrías de Equilibrio para Aglomeraciones de 1,2-propanodiol con 3, 4, 5 y 6 Moléculas de Agua

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