title: HPTLC and magnetochromatography of new complexes of carboxylates with transition metals or rare earth elements and their ligands - study of lipophilicity.
abstract: Nineteen new complexes of carboxylates with transition and rare elements as central ions and their ligands were characterized by chromatographic analyses. The parameter of relative lipophilicity (RM0) of the tested compounds was determined experimentally by the reversed-phase high-performance thin layer chromatography method with mixtures of various organic modifiers (acetonitrile, acetone, dioxane) and water as a mobile phase. The extrapolated RM0values were compared with the logP values calculated from the molecular structures of tested solutes. Similarities between the lipophilicity indices were analysed by principal component analysis and linear regression. Thin-layer chromatography combined with a magnetic field has been proposed as a complementary method for determination of lipophilicity of the investigated compounds. The chromatograms in the field and outside it were developed simultaneously in two identical chromatographic chambers. One of them was placed in the external magnetic field of 0.4 T inductivity. We proved that chelation causes a drastic change in compound lipophilicity, but all complexes did not exhibit enhanced activity as compared with the parent ligand. Also in the magnetic field the retention of some complexes changed, which means that the presence of the field influences the physicochemical properties of the compounds and their interactions with the stationary phase.
authors.affiliation: Department of Planar Chromatography, Chair of Physical Chemistry, Faculty of Chemistry, Maria Curie-Skłodowska University, Lublin, Poland.
authors.forename: Irena
authors.initials: I
authors.lastname: Malinowska
authors.affiliation: Department of Planar Chromatography, Chair of Physical Chemistry, Faculty of Chemistry, Maria Curie-Skłodowska University, Lublin, Poland.
authors.forename: Agnieszka
authors.initials: A
authors.lastname: Wronka
authors.affiliation: Department of General and Coordination Chemistry, Maria Curie-Skłodowska University, Lublin, Poland.
authors.forename: Wiesława
authors.initials: W
authors.lastname: Ferenc
mesh_terms: D056148:Chromatography, Reverse-Phase / Q000379:methods; D002855:Chromatography, Thin Layer / Q000379:methods*; D056831:Coordination Complexes / Q000032:analysis / Q000737:chemistry*; D057927:Hydrophobic and Hydrophilic Interactions; D008280:Magnetics; D008670:Metals / Q000737:chemistry; D015394:Molecular Structure
chemical_list: D056831:Coordination Complexes; D008670:Metals
keywords: PCA; TLC; carboxylates; lipophilicity; magneto-chromatography; metalorganic compound; rare earth elements