Excess protons in mesoscopic water-acetone nanoclusters

Mostrar todas las versiones(3)

We carried out molecular dynamics simulation experiments to examine equilibrium and dynamical characteristics of the solvation of excess protons in mesoscopic, [m:n] binary polar clusters comprising m 50 water molecules and n 6, 25, and 100 acetone molecules. Contrasting from what is...

Descripción completa

Guardado en:

Detalles Bibliográficos
Autores principales:	Semino, R., Martí, J., Guàrdia, E., Laria, D.
Formato:	Artículo publishedVersion
Publicado:	2012
Materias:	Acetone molecules Aprotic Aqueous phase Cluster morphology Cluster structure Concentration fluctuation Diffusive motions Dynamical characteristics Exchange process Inner region Irregular shape Mesoscopics Mixing process Molecular dynamics simulations Nano-second time domain Polar cluster Proton solvation Relative concentration Solvation shell Time-scales Transfer mechanisms Translocation pathway Water molecule Molecular dynamics Molecules Proton transfer Solvation Superconducting materials Acetone
Acceso en línea:	http://hdl.handle.net/20.500.12110/paper_00219606_v137_n19_p_Semino http://repositoriouba.sisbi.uba.ar/gsdl/cgi-bin/library.cgi?a=d&c=artiaex&d=paper_00219606_v137_n19_p_Semino_oai
Aporte de:	Repositorio Digital de la Universidad de Buenos Aires (UBA) de Universidad de Buenos Aires

id	I28-R145-paper_00219606_v137_n19_p_Semino_oai
record_format	dspace
spelling	I28-R145-paper_00219606_v137_n19_p_Semino_oai2020-10-19 Semino, R. Martí, J. Guàrdia, E. Laria, D. 2012 We carried out molecular dynamics simulation experiments to examine equilibrium and dynamical characteristics of the solvation of excess protons in mesoscopic, [m:n] binary polar clusters comprising m 50 water molecules and n 6, 25, and 100 acetone molecules. Contrasting from what is found in conventional macroscopic phases, the characteristics of the proton solvation are dictated, to a large extent, by the nature of the concentration fluctuations prevailing within the clusters. At low acetone contents, the overall cluster morphology corresponds to a segregated aqueous nucleus coated by an external aprotic phase. Under these circumstances, the proton remains localized at the surface of the water core, in a region locally deprived from acetone molecules. At higher acetone concentrations, we found clear evidence of the onset of the mixing process. The cluster structures present aqueous domains with irregular shape, fully embedded within the acetone phase. Still, the proton remains coordinated to the aqueous phase, with its closest solvation shell composed exclusively by three water molecules. As the relative concentration of acetone increases, the time scales characterizing proton transfer events between neighboring water molecules show considerable retardations, stretching into the nanosecond time domain already for n ∼ 25. In water-rich aggregates, and similarly to what is found in the bulk, proton transfers are controlled by acetone/water exchange processes taking place at the second solvation shell of the proton. As a distinctive feature of the transfer mechanism, translocation pathways also include diffusive motions of the proton from the surface down into inner regions of the underlying water domain. © 2012 American Institute of Physics. Fil:Semino, R. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales; Argentina. Fil:Laria, D. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales; Argentina. application/pdf http://hdl.handle.net/20.500.12110/paper_00219606_v137_n19_p_Semino info:eu-repo/semantics/openAccess http://creativecommons.org/licenses/by/2.5/ar J Chem Phys 2012;137(19) Acetone molecules Aprotic Aqueous phase Cluster morphology Cluster structure Concentration fluctuation Diffusive motions Dynamical characteristics Exchange process Inner region Irregular shape Mesoscopics Mixing process Molecular dynamics simulations Nano-second time domain Polar cluster Proton solvation Relative concentration Solvation shell Time-scales Transfer mechanisms Translocation pathway Water molecule Molecular dynamics Molecules Proton transfer Solvation Superconducting materials Acetone Excess protons in mesoscopic water-acetone nanoclusters info:eu-repo/semantics/article info:ar-repo/semantics/artículo info:eu-repo/semantics/publishedVersion http://repositoriouba.sisbi.uba.ar/gsdl/cgi-bin/library.cgi?a=d&c=artiaex&d=paper_00219606_v137_n19_p_Semino_oai
institution	Universidad de Buenos Aires
institution_str	I-28
repository_str	R-145
collection	Repositorio Digital de la Universidad de Buenos Aires (UBA)
topic	Acetone molecules Aprotic Aqueous phase Cluster morphology Cluster structure Concentration fluctuation Diffusive motions Dynamical characteristics Exchange process Inner region Irregular shape Mesoscopics Mixing process Molecular dynamics simulations Nano-second time domain Polar cluster Proton solvation Relative concentration Solvation shell Time-scales Transfer mechanisms Translocation pathway Water molecule Molecular dynamics Molecules Proton transfer Solvation Superconducting materials Acetone
spellingShingle	Acetone molecules Aprotic Aqueous phase Cluster morphology Cluster structure Concentration fluctuation Diffusive motions Dynamical characteristics Exchange process Inner region Irregular shape Mesoscopics Mixing process Molecular dynamics simulations Nano-second time domain Polar cluster Proton solvation Relative concentration Solvation shell Time-scales Transfer mechanisms Translocation pathway Water molecule Molecular dynamics Molecules Proton transfer Solvation Superconducting materials Acetone Semino, R. Martí, J. Guàrdia, E. Laria, D. Excess protons in mesoscopic water-acetone nanoclusters
topic_facet	Acetone molecules Aprotic Aqueous phase Cluster morphology Cluster structure Concentration fluctuation Diffusive motions Dynamical characteristics Exchange process Inner region Irregular shape Mesoscopics Mixing process Molecular dynamics simulations Nano-second time domain Polar cluster Proton solvation Relative concentration Solvation shell Time-scales Transfer mechanisms Translocation pathway Water molecule Molecular dynamics Molecules Proton transfer Solvation Superconducting materials Acetone
description	We carried out molecular dynamics simulation experiments to examine equilibrium and dynamical characteristics of the solvation of excess protons in mesoscopic, [m:n] binary polar clusters comprising m 50 water molecules and n 6, 25, and 100 acetone molecules. Contrasting from what is found in conventional macroscopic phases, the characteristics of the proton solvation are dictated, to a large extent, by the nature of the concentration fluctuations prevailing within the clusters. At low acetone contents, the overall cluster morphology corresponds to a segregated aqueous nucleus coated by an external aprotic phase. Under these circumstances, the proton remains localized at the surface of the water core, in a region locally deprived from acetone molecules. At higher acetone concentrations, we found clear evidence of the onset of the mixing process. The cluster structures present aqueous domains with irregular shape, fully embedded within the acetone phase. Still, the proton remains coordinated to the aqueous phase, with its closest solvation shell composed exclusively by three water molecules. As the relative concentration of acetone increases, the time scales characterizing proton transfer events between neighboring water molecules show considerable retardations, stretching into the nanosecond time domain already for n ∼ 25. In water-rich aggregates, and similarly to what is found in the bulk, proton transfers are controlled by acetone/water exchange processes taking place at the second solvation shell of the proton. As a distinctive feature of the transfer mechanism, translocation pathways also include diffusive motions of the proton from the surface down into inner regions of the underlying water domain. © 2012 American Institute of Physics.
format	Artículo Artículo publishedVersion
author	Semino, R. Martí, J. Guàrdia, E. Laria, D.
author_facet	Semino, R. Martí, J. Guàrdia, E. Laria, D.
author_sort	Semino, R.
title	Excess protons in mesoscopic water-acetone nanoclusters
title_short	Excess protons in mesoscopic water-acetone nanoclusters
title_full	Excess protons in mesoscopic water-acetone nanoclusters
title_fullStr	Excess protons in mesoscopic water-acetone nanoclusters
title_full_unstemmed	Excess protons in mesoscopic water-acetone nanoclusters
title_sort	excess protons in mesoscopic water-acetone nanoclusters
publishDate	2012
url	http://hdl.handle.net/20.500.12110/paper_00219606_v137_n19_p_Semino http://repositoriouba.sisbi.uba.ar/gsdl/cgi-bin/library.cgi?a=d&c=artiaex&d=paper_00219606_v137_n19_p_Semino_oai
work_keys_str_mv	AT seminor excessprotonsinmesoscopicwateracetonenanoclusters AT martij excessprotonsinmesoscopicwateracetonenanoclusters AT guardiae excessprotonsinmesoscopicwateracetonenanoclusters AT lariad excessprotonsinmesoscopicwateracetonenanoclusters
_version_	1766026572704251904

Excess protons in mesoscopic water-acetone nanoclusters

Ejemplares similares