title: Molecular dynamics study of the calcium ion transfer across the water/nitrobenzene interface.
abstract: A study on the calcium ion transfer across the water/nitrobenzene interface is presented. The potential of mean force was calculated and a good agreement was found between the experimental and the calculated free energy of transfer. This is a monotonically increasing function of the distance to the interface, and the process was found to be non-activated. The evolution of the first and second hydration shells was analysed as a function of the distance to the interface; the first hydration shell remains intact whereas the second hydration shell suffers a severe water loss. Water finger formation was also found, with behaviour similar to that already described for other ions in different interfaces. As far as we know, a direct comparison between the calculated number of water molecules dragged with an ion into the organic phase and the experimental results is presented for the first time and a very good agreement was found.
authors.affiliation: Departamento de Química da Faculdade de Ciências Universidade do Porto R. Campo Alegre 687, 4069-007 Porto, Portugal. dasantos@fc.up.pt
authors.forename: Daniel J V A
authors.initials: DJ
authors.lastname: dos Santos
authors.forename: José A N F
authors.initials: JA
authors.lastname: Gomes
mesh_terms: D002118:Calcium / Q000737:chemistry*; D004058:Diffusion; D008954:Models, Biological; D009578:Nitrobenzenes / Q000737:chemistry; D014867:Water / Q000737:chemistry
chemical_list: D009578:Nitrobenzenes; D014867:Water; C036077:nitrobenzene; D002118:Calcium