title: Descriptors for ions and ion-pairs for use in linear free energy relationships.
abstract: The determination of Abraham descriptors for single ions is reviewed, and equations are given for the partition of single ions from water to a number of solvents. These ions include permanent anions and cations and ionic species such as carboxylic acid anions, phenoxide anions and protonated base cations. Descriptors for a large number of ions and ionic species are listed, and equations for the prediction of Abraham descriptors for ionic species are given. The application of descriptors for ions and ionic species to physicochemical processes is given; these are to water-solvent partitions, HPLC retention data, immobilised artificial membranes, the Finkelstein reaction and diffusion in water. Applications to biological processes include brain permeation, microsomal degradation of drugs, skin permeation and human intestinal absorption. The review concludes with a section on the determination of descriptors for ion-pairs.
authors.affiliation: Department of Chemistry, University College London, 20 Gordon Street, London WC1H OAJ, UK. Electronic address: m.h.abraham@ucl.ac.uk.
authors.forename: Michael H
authors.initials: MH
authors.lastname: Abraham
authors.affiliation: Department of Chemistry, P.O. Box 305070, University of North Texas, Denton, TX 76203-5070, USA.
authors.forename: William E
authors.initials: WE
authors.lastname: Acree
mesh_terms: D000838:Anions / Q000737:chemistry*; D001921:Brain / Q000378:metabolism; D002264:Carboxylic Acids / Q000737:chemistry; D002412:Cations / Q000737:chemistry*; D002851:Chromatography, High Pressure Liquid; D004058:Diffusion; D006801:Humans; D007408:Intestinal Absorption; D008567:Membranes, Artificial; D008861:Microsomes / Q000378:metabolism; D004364:Pharmaceutical Preparations / Q000378:metabolism; D012867:Skin / Q000378:metabolism; D012997:Solvents / Q000737:chemistry; D013816:Thermodynamics; D014867:Water / Q000737:chemistry
chemical_list: D000838:Anions; D002264:Carboxylic Acids; D002412:Cations; D008567:Membranes, Artificial; D004364:Pharmaceutical Preparations; D012997:Solvents; D014867:Water
keywords: Biochemical processes; Ion-pairs; Ionic species; Ions; Linear free energy relationship; Physicochemical processes