21-(9-Anthrylmethyl)-4,17,13,16-tetraoxa-1,10,21-triazabicycle[8.8.5]tricosane-19,23-dione (I) was synthesized and characterized as a fluoroionophore for the selective, optical detection of lithium ions. The compound was prepared in a conventional four step synthesis. I is based on a bridged diazacrown structure, which provides a semi-rigid binding framework. Binding takes place by electrostatic interactions between the oxygen atoms of the crown and the cation and is transduced to fluorescence emission from an attached anthracene fluorophore. In a 3:1 dichloromethane/tetrahydrofuran solvent mixture, I acts as an intramolecular electron transfer 'off-on' fluorescence switch, exhibiting a greater than 190-fold enhancement in fluorescence emission intensity in the presence of lithium ions. The relative selectivity of I for lithium ions over sodium, potassium and ammonium ions expressed as log K (where more negative values indicate higher selectivity) were log K Li+,Na+ = - 3.36, log K Li+,K+ = - 1.77 and log K Li+,NH4+ = - 2.78. 21-(16-Mercaptohexadecan-1-oyl)-4,7,13,16-tetraoxa-1,10,21-triazabicyclo-[8.8.5]trico sine-19,23-dione (II) was synthesized in six steps using conventionalmethods. 11-Mercapto-N-(4-(9,15,18-triisopropyl-6,12-dimethyl-2,5,8,11,14,17-hexaoxo-1,7,13-trioxa-4,10,16-triazacyclooctadecan-3-yl)butyl) undecan-amide (III) was synthesized in fifteen steps with an orthogonal protecting group strategy. These molecules were prepared as a self-assembled monolayer (SAM) on gold. Characterization of a gold surface modified with II and III was carried out by sessile drop contact angle goniometry, ellipsometry, and grazing angle FT-IR spectroscopy. The cation recognition properties of the SAM were studied by impedance spectroscopy. The films of II show selectivity for lithium ions in solution over potassium and sodium ions, with selectivity values: log K Li+,Na+ = -1.30 and log K Li+,K+ = -0.92. The films of III showed selectivity for ammonium ions in aqueous solution over potassium and sodium ions, with selectivity values calculated to be log K NH4+,Na+ = -1.23 and log K NH4+,K+ = -1.17. To the best of our knowledge, these are the first demonstrations of lithium and ammonium sensors fabricated using self-assembled monolayer technology. Compounds IV and V are macrobicyclic compounds designed and synthesized as ammonium selective ionophores for use in ion selective electrode (ISE) applications. The structures of IV and V are based on bicyclic depsipeptide motifs which are expected to provide binding sites for ammonium ions due to the tetrahedral arrangement of carbonyl groups that participate in hydrogen bonding interactions. The synthesis of compound IV, involving 22 steps, was unsuccessful, potentially due to steric effects on the final (second) cyclization. The alternative molecule (V) was successfully synthesized in six steps using solution phase and solid phase peptide synthesis. Ionophore V incorporated into an ISE format provided selectivity for ammonium ions over sodium ions (log K NH4+, Na+ ~ - 0.08 to -0.47), however it did not show selectivity for ammonium ions over potassium ions (log K K+,NH4+ ~ -0.47 to - 0.61).

A range of novel silver ionophores was synthesised based on the l,3-dithiole-2- thione-4,5-dithiolate (DMIT) building block. These were incorporated in ion-selective electrodes (ISEs) and applied to the determination of silver ion in photographic process solutions of interest to Kodak. Two classes of compounds were synthesised incorporating acyclic silver binding sites. The first class of compounds were 1,3 dithiole-2-ones functionalised with (i) a silver binding chain, and (ii) an alkyl chain, the latter allowing a range of compounds to be synthesised of varying lipophilicity. These compounds were applied as silver ionophores in plasticised PVC membranes and incorporated in ion-selective electrodes. The newly synthesised ionophores were compared to silver ionophores in the literature and to those previously used by Kodak. The membrane composition was optimised for silver ion selectivity over a range of metal cations of relevance to photographic process solutions. Samples of photographic emulsions were supplied by Kodak and subsequent analysis demonstrated successful detection of silver ion to micromolar levels with the ISE incorporating the newly synthesised ionophores. The second class of compounds was based on the tetrathiafulvalene (TTF) building block. A TTF derivative was synthesised incorporating two acyclic silver binding chains and a hydrophobic domain. The reversible redox properties of this compound enabled it to be applied as a transducer suitable for voltammetric analysis of silver ion. Titration of a solution of the new TTF compound with silver ion revealed that it was very sensitive; an equimolar quantity of silver ion resulting in a marked change in voltammetric behaviour. A silver ion binding constant was determined by ultraviolet spectrophotometry.

Thesis (Ph. D.)--University of Wisconsin--Madison, 1985. / Typescript. Vita. eContent provider-neutral record in process. Description based on print version record. Includes bibliographical references (leaves 216-221).

A variety of novel cage-functionalized pyridyl containing crown ethers have been prepared for use in selective alkali metal complexation studies. A highly preorganized, cage-functionalized cryptand also has been designed and has been synthesized for use as a selective Li+ complexant. The alkali metal picrate extraction profiles of these cage-functionalized crown ethers also have been studied. Novel cage-functionalized diazacrown ethers have been prepared for selective alkali metal complexation studies. Alkali metal picrate extraction experiments have been performed by using this new class of synthetic ionophores to investigate the effects of cage-annulation and the influence of N-pivot lariat sidearms upon their resulting complexation properties. Novel pyridyl containing calix[4]arene receptors were prepared. Analysis of their respective 1H NMR and 13C NMR spectra suggests that calix[4]arene moieties in the ligand occupy the cone conformation. The complexation properties of these host molecules were estimated by performing a series of alkali metal picrate extraction experiments. An optically active cage-functionalized crown ether which contains a binaphthyl moiety as the chiral unit was prepared. The ability of the resulting optically active crown ether to distinguish between enantiomers of guest ammonium ions (i.e., phenylethylamonium and phenylglycinate salts) in transport experiments was investigated. Hexacyclo[11.2.1.02,12.05,10.05,15.010,14]hexadeca-6,8-diene-4,11-dione was prepared from hexacyclo[7.4.2.01,9.03,7.04,14.06,15] pentadeca-10,12-diene-2,8-dione. Unanticipated but remarkable acid and base promoted rearrangements of this new cage dione to novel polycyclic systems were observed and subsequently were investigated. The structures of the new systems thereby obtained were determined unequivocally by application of X-ray crystallographic methods. It is noteworthy that the reactions reported herein each provide the corresponding rearranged product in high yield in a single synthetic step. Pi-facial and regioselectivity in the thermal Diels-Alder cycloaddition between hexacyclo[11.2.1.02,12.05,10.05,15.010,14]hexadeca-6,8-diene- 4,11-dione and ethyl propiolate have been explored. This reaction proceeds via stereospecific approach of the dienophile toward the syn face of the diene p -system. However, [4+2]cycloaddition proceeds with only modest proximal/distal regioselectivity. The structure of the minor reaction product was established unequivocally via application of X-ray crystallographic techniques.

The rational design, synthesis and complexation characteristics of several monovalent cation-selective ligands are described. Molecular modeling employing a combination of dynamics, mechanics (AMBER94) and electrostatics was used to design ligands for the complexation of ammonium, potassium, sodium and lithium ions. A modular technique was used to synthesize an ammonium selective ionophore based on a cyclic depsipeptide structure (8). The ionophore was incorporated into a planar ion selective electrode (ISE) sensor format and the selectivity tested versus a range of metal cations. It was found that the membrane containing the polar plasticizer NPOE (nitrophenyloctylether) in the absence of ionic additive exhibited near-Nernstian behavior (slope = 60.1 mV/dec @ 37¢ªC) and possessed high selectivity for ammonium ion over lithium and the divalent cations, calcium and magnesium (logK = -7.3, -4.4, -7.1 for lithium, calcium and magnesium ions, respectively). The same membrane also exhibited sodium and potassium selectivity that was comparable to that reported for nonactin (logK = -2.1, -0.6 for sodium and potassium, respectively, compared to -2.4, -0.9 in the case of nonactin). N-(9-methylanthracene)-25,27-bis(1-propyloxy)calix[4]arene-azacrown-5 (10) was synthesized and tested as a fluoroionophore for the selective detection of potassium ions. Compound 10 acts as an ¡°off-on¡± fluorescent indicator for ion complexation as a result of photoinduced intramolecular electron transfer (PET). Studies demonstrate that 10 is selective for potassium over other alkali metal cations, with excellent selectivity over sodium and lithium (log K ¡ -3.5) and moderate selectivity over rubidium and cesium (log K ~ -1). N-(9-methylanthracene)-25,27-bis(1-propyloxy)-4-tert-butylcalix[4]arene-azacrown-3 (11) was synthesized and tested as a fluoroionophore for the selective detection of lithium cations. When exposed to lithium ions in a 75:25 dichloromethane/THF solvent mixture, the molecule, which operates on PET, exhibited a >106-fold enhancement in fluorescence emission intensity. Selectivity studies demonstrated that 11 effectively discriminates against sodium and potassium ions log K ¡ -3.8 and log K ¡ -2.3. A fluorescent sodium optode based on a fluoroionophore consisting of aminorhodamine B covalently-linked through an amide bond to a calix[4]arene has also been developed (12). The optode, fashioned by incorporation of the fluoroionophore into a single component polymer matrix, operates on the basis of PET. The fluorescence intensity increased linearly with increasing sodium ion concentration in the range 0.01 M to 2.0 M, exhibiting a three-fold enhancement over this range. The optode provides selectivity for sodium ions compared to potassium ions that is sufficient for clinical determinations of sodium ion concentration.

No description available.

Thesis (Ph. D.)--Ohio State University, 2006. / Title from first page of PDF file. Includes bibliographical references (p. 148-156).

Reproduction de : Thèse de doctorat : Sciences de la vie : Poitiers : 2008. / Contient des textes en anglais, extraits de différentes publications et revues. Titre provenant de l'écran-titre. Bibliogr. 268 réf.

Thesis (Ph. D.)--Oregon State University, 2010. / Printout. Includes bibliographical references. Also available on the World Wide Web.

Thesis (M.S.)--Worcester Polytechnic Institute. / Keywords: sensor, synthesis, bicyclic, fluoroionophore, nonactin, ion-selective, ammonium. Includes bibliographical references (leaves 117-119 ).