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Anion Interactions (anion + interaction)
Selected AbstractsThe ,-Accepting Arene HAT(CN)6 as a Halide Receptor through Charge Transfer: Multisite Anion Interactions and Self-Assembly in Solution and the Solid State,ANGEWANDTE CHEMIE, Issue 40 2010Dr. Helen T. Chifotides Sensibles Selbstorganisat: Ihre außergewöhnliche ,-Elektronenakzeptorstärke macht die Titelverbindung zu einem exzellenten kolorimetischen Halogenidsensor. Neu daran ist, dass HAT(CN)6 mit Anionen multiple Wechselwirkungen (sowohl Charge-Transfer als auch Anion-,) in Lösung und im Festkörper eingeht. Die Halogenidionen bewirken die spontane Selbstorganisation der Sandwichkomplexe über ,2,,2 -Ladungstransferkontakte. [source] Towards a Molecular Understanding of Cation,Anion Interactions,Probing the Electronic Structure of Imidazolium Ionic Liquids by NMR Spectroscopy, X-ray Photoelectron Spectroscopy and Theoretical CalculationsCHEMISTRY - A EUROPEAN JOURNAL, Issue 30 2010Till Cremer Abstract Ten [C8C1Im]+ (1-methyl-3-octylimidazolium)-based ionic liquids with anions Cl,, Br,, I,, [NO3],, [BF4],, [TfO],, [PF6],, [Tf2N],, [Pf2N],, and [FAP], (TfO=trifluoromethylsulfonate, Tf2N=bis(trifluoromethylsulfonyl)imide, Pf2N=bis(pentafluoroethylsulfonyl)imide, FAP=tris(pentafluoroethyl)trifluorophosphate) and two [C8C1C1Im]+ (1,2-dimethyl-3-octylimidazolium)-based ionic liquids with anions Br, and [Tf2N], were investigated by using X-ray photoelectron spectroscopy (XPS), NMR spectroscopy and theoretical calculations. While 1H,NMR spectroscopy is found to probe very specifically the strongest hydrogen-bond interaction between the hydrogen attached to the C2 position and the anion, a comparative XPS study provides first direct experimental evidence for cation,anion charge-transfer phenomena in ionic liquids as a function of the ionic liquid's anion. These charge-transfer effects are found to be surprisingly similar for [C8C1Im]+ and [C8C1C1Im]+ salts of the same anion, which in combination with theoretical calculations leads to the conclusion that hydrogen bonding and charge transfer occur independently from each other, but are both more pronounced for small and more strongly coordinating anions, and are greatly reduced in the case of large and weakly coordinating anions. [source] Sulfide anion interaction with Cu(1 0 0) and Cu modified Au(1 0 0): An electrochemical STM studyPHYSICA STATUS SOLIDI (A) APPLICATIONS AND MATERIALS SCIENCE, Issue 2 2010Christian Schlaup Abstract We describe the formation of thin copper sulfide semiconductor films under electrochemical conditions. In a first step we investigated the fundamental interaction of the Cu(1 0 0) surface with a sulfide anions containing electrolyte. Beside the classical p(2,×,2)-S and c(2,×,6)-S adlayer phases we found the formation of a closer packed "pseudo- c(2,×,2)"-S phase accompanied by an expansion of the topmost copper layer. For a further investigation of this "pseudo- c(2,×,2)"-S phase, we switched from the bulk Cu(1 0 0) electrode to a copper monolayer on a Au(1 0 0) electrode, which can be easily prepard using copper underpotential deposition. Since such a copper monolayer is pseudomorphic to the Au(1 0 0) surface and therefore expanded by 12.5% with respect to the bulk Cu(1 0 0)-plane, exclusively a commensurate c(2,×,2)-S structure is instantaneously formed and remains stable over a wide potential range. [source] Bisamides Derived from Azulene-1,3- and -5,7-dicarboxylic Acids as New Building Blocks for Anion ReceptorsCHEMISTRY - A EUROPEAN JOURNAL, Issue 3 2008Tomasz Zieli, ski Dr. Abstract Bisamides based on the azulene moiety were investigated as building blocks for anion receptors. In the course of these studies, derivatives of azulene-1,3- and -5,7-dicarboxylic acid were synthesized and thoroughly characterized. The anion affinities of the derivatives based on functionalization in the five-membered ring and in the seven-membered ring were determined by 1H,NMR titration. The structural analysis of these building blocks was performed by X-ray diffractometry, molecular modelling and 2D NMR spectroscopy. The five-membered ring derivatives are easy to obtain, offer a binding site preorganized in the syn,syn conformation and bind anions with a strength similar to those of pyrrole-based analogues. There is also strong evidence for aromatic CH,,,anion interactions. The ligands substituted at the 5- and 7-positions offer a binding cleft with an uncommon geometry that originates from the seven-membered ring and seems to be complementary to the chloride anion. [source] | ||||||||||