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1	The Physical Properties of Mixed-Valence 1',1'"-bis(2,2':6',2"-terpyridin-4'-yl)-1,1"-biferrocenium Complexes ¡G Mössbauer and EPR Characteristics. Chang, Ya-Ting 03 July 2003 (has links) none Mixed-Valence electron transfer counter ion nanowire
2	Characterizing Salinity Tolerance in Greenhouse Roses Solis Perez, Alma R. 2009 May 1900 (has links) Among ornamental plants, roses (Rosa L.) are considered the most economically important, being among the most popular garden shrubs, as well as the favorite cut flowers sold by florists. In the past roses have been classified as fairly salt-sensitive, however, recent nutrition studies suggest that they may actually tolerate moderate to relatively high salinities. The general objective of this research was to reassess the limits of tolerance to salinity of roses and the influence of the rootstock used, to determine the ameliorative properties of supplemental Ca2+ on the response to salt stress, and to establish the influence of Na+- and Cl--counter ions on the detrimental effects caused by these salinizing elements. The NaCl or NaCl-CaCl2-salinity tolerance limit for greenhouse roses, although greatly influenced by the rootstock, was between 12 and 15 mmol.L-1. Plants grafted on ?Manetti? sustained their productivity/quality characteristics for longer time periods, tolerated greater salinity concentrations, and accumulated less Cl- and Na+ in leaves of flowering shoots than those grafted on ?Natal Briar?, confirming the greater ability of the former rootstock to tolerate salt stress. Supplementing the saline solution with 0-10 mmol.L-1 Ca2+ (as CaSO4) did not alleviate the harmful effects caused by NaCl-salt stress (12 mmol.L-1) on the productivity and quality responses of roses. The detrimental effects caused by Na- and Cl-based salinity were greatly influenced by the composition of the salt mixtures (i.e. their counter ions). Sodium sulfate and CaCl2 were the least harmful salts; NaCl had intermediate effects, while NaNO3 and KCl were the most deleterious. Among the most distinguishable effects caused by the more toxic Na+ and Cl- counter ions were lower osmotic potential (piSS) and greater electrical conductivity (ECSS) of the salinized solutions, markedly increased uptake and/or transport of either Na+ or Cl- to the flowering shoot leaves, and altered uptake and/or transport of other mineral nutrients. Computations of the saline solutions? chemical speciation revealed that salts containing divalent ions had lower ionization and exhibited greater ion associations compared to monovalent ion salts, rendering a lower number in free ions/molecules in solution which caused greater SS and lower ECSS in those solutions. sodicity in roses Na-counter ion effects Cl-counter ion effects specific ion effects osmotic effects supplemental calcium Na/Ca ratios salinity tolerance limits of roses alleviating salinity effects salinity effects of rose nutrition irrigation water quality
3	Enantiomeric Separations using Chiral Counter-Ions Haglöf, Jakob January 2010 (has links) This thesis describes the use of chiral counter-ions for the enantiomeric separation of amines in non-aqueous capillary electrophoresis. The investigations have been concentrated on studies of the influence, of the chiral counter-ion, the solvent, the electrolyte and the analyte, on the enantioselective separation. Modified divalent dipeptides have been introduced in capillary electrophoresis for the separation of amino alcohols and chiral resolution of amines. Association constants for the ion-pair between dipeptide and amino alcohol could be utilized for development of separation systems with higher amino alcohol selectivity. Chiral discrimination (ion-pair formation) between the dipeptides and amines are preferably generated in non-aqueous background electrolytes (BGEs). The amount of triethylamine in the BGE determined the dipeptide charge and a divalent dipeptide promoted higher enantioselectivity than a monovalent dipeptide. An N-terminal-end blocking group and glutamic acid at the C-terminal-end of the dipeptide was important for chiral separation of the amines. Chemometric and univariate methods have been employed for evaluation of suitable solvent compositions in the BGE. An experimental design including a single solvent as well as binary, ternary and quaternary mixtures of polar organic solvents, showed that optimal enantioresolution was obtained with an ethanol:methanol 80:20 mixture in the BGE. Furthermore, water was found to have an adverse influence on enantioselectivity and no enantioresolution was obtained with BGEs containing more than 30 % water. An alkali metal hydroxide added to the BGE affected the chiral separation by competing ion-pair formation with the selector. The electroosmosis was reduced in order of decreasing alkali metal ion solvated radius and became anodic using K, Rb or Cs in ethanolic BGEs. The correlation between the amino alcohol structure and the enantioselectivity was investigated using chemometrics. The obtained models showed that enantioselectivity for the amino alcohols was promoted by e.g. degree of substitution and substituent size on the nitrogen. Capillary Electrophoresis Chiral Counter-Ion Divalent Dipeptide Enantioselectivity Electroosmosis Chemometrics Molecular Descriptor Pharmaceutical chemistry Farmaceutisk kemi
4	Nano/micro auto-assemblages chiraux de tensioactifs cationiques : du comportement dynamique des architectures supramoléculaires jusqu’aux nanomatériaux hybrides / Chiral nano/micro self-assemblies of cationic surfactants : from dynamic behavior of supramolecular architectures towards hybrid nanomaterials Tamoto, Rumi 19 December 2011 (has links) Nous avons étudié les comportements dynamiques d'auto-assemblage des tensioactifs cationiques non-chiral en présence du contre-anion chiral.Lorsque le nucléotide anionique chiral est ajouté à des vésicules cationiques, la transition morphologique se produit et transforme in situ des vésicules sphériques en hélices micrométriques.D'autres types de Gemini tensioactifs cationiques forment des rubans nanométriques hélicoïdaux, en présence de tartrate contre-anions. La forme et l'hélicité de ces rubans peuvent être contrôlés in situ par la variation de l'excès énantiomérique.En outre, les nanohélices organiques peuvent être transcrite en nanohélices 3D de silice via une polycondensation sol-gel.Ces nanohélices de silice fonctionnalisées avec des groupes aminés peuvent interagir fortement avec des nanoparticules d'or (GNPs; 1 ~ 20 nm). Le réseau 3D de -nanohélices GNPs/silice sont potentiellement utilisables pour des applications de capteurs basée sur les SERS comme ceux chimiques et biologiques ultra-sensibles en phase liquide. / We have studied the dynamic self-assembly behaviors of non-chiral cationic surfactants in thepresence of chiral counter-anion.When the chiral anionic nucleotides are added to cationic vesicles, morphology transitionoccurs and spherical vesicles transform in situ to micrometric helices.Other types of cationic surfactant, gemini surfactants form nanometric helical ribbons in thepresence of tartrate counter-anion. The shape and helicity of these self-assembled structurescan be controlled in situ by the variation of enantiomeric excess.In both cases, they form gels in water by creating extended networks of nanometric tomicrometric chiral fibers.Additionally, the organic nanohelices can be transcribed to 3D silica nanostructures via solgelpolycondensation. These silica nanohelices functionalized with amino group can interactstrongly with gold nanoparticles (1 ~ 20 nm). The 3D network of GNPs/silica-nanohelices canpotentially be used for SERS-based sensing applications such as ultra-sensitive chemical andbiological sensors in liquid phase. Amphiphiles chiraux Transformation de morphologie Echange de cotre-ion SERS Nanomatériaux hybrides Architectures supramoléculaires Chiral amphiphiles Morphology transformation Counter-ion exchange SERS Hybrid nanomaterials Supramolecular structures
5	From Copper to Gold: Identification and Characterization of Coinage-Metal Ate Complexes by ESI Mass Spectrometry and Gas-Phase Fragmentation Experiments Weske, Sebastian 30 January 2019 (has links) No description available. 540 coinage metal copper silver gold cuprate argentate aurate ate complex organocuprate organoargentate organoaurate magnesium organocuprate normant cuprate Cu(I) Cu(III) Ag(I) Ag(III) trifluoromethylation copper-mediated trifluoromethylation ruppert prakash c-c coupling cross coupling silver-mediated cross-coupling reactive intermediate reductive elimination counter ion effect esi ms esi-ms gas-phase fragmentation collision-induced dissociation cid gas-phase experiment gas-phase chemistry ion chemistry curiosity driven research Chemie (PPN62138352X)

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