title: Interaction of dodecaborate cluster compounds on hydrophilic column materials in water.
abstract: The interaction of a series of dodecaborate cluster compounds B(12)X(12)(2-) and B(12)X(11)Y(2-) (X=H, Cl, Br, I and Y=SH, OH, NR(3)) with hydrophilic column materials (Superdex 200, Sepharose 4B, Sephadex G-50, Sephadex G-100, alumina, silica gel and anion exchange material) was studied. Almost all the dodecaborate cluster compounds were retained strongly on Superdex 200. The halogenated cluster compounds interacted with Sepharose 4B, Sephadex G-50, Sephadex G-100 and alumina; on alumina, also the non-halogenated clusters were retained. Silica gel showed the least interaction with all compounds. The thermodynamic parameters were investigated for a selection of compounds on Superdex 200 and Sephadex G-100. Values for ΔH° were found to be negative on both gels. As the change in entropy ΔS° was also negative, it compensated ΔH° to a large extent. The clusters interacted also strongly with anion exchange material in ion chromatography; the interaction decreased with increasing acetonitrile concentration, implying a large contribution from solvent effects.
authors.affiliation: Department of Chemistry, University of Bremen, Germany.
authors.forename: Ping
authors.initials: P
authors.lastname: Fan
authors.forename: Jennifer
authors.initials: J
authors.lastname: Neumann
authors.forename: Stefan
authors.initials: S
authors.lastname: Stolte
authors.forename: Jürgen
authors.initials: J
authors.lastname: Arning
authors.forename: Denise
authors.initials: D
authors.lastname: Ferreira
authors.forename: Katarina
authors.initials: K
authors.lastname: Edwards
authors.forename: Detlef
authors.initials: D
authors.lastname: Gabel
mesh_terms: D001896:Boron Compounds / Q000737:chemistry*; D002851:Chromatography, High Pressure Liquid; D008962:Models, Theoretical; D013816:Thermodynamics; D014867:Water / Q000737:chemistry*
chemical_list: D001896:Boron Compounds; D014867:Water; C119788:dodecaborate