Kye Chun Nam

Calixarenes. 22. Synthesis, properties, and metal complexation of aminocalixarenes

Preparation de calix [4] arene et de derives fonctionnalises. Formation de complexes avec Ni, Cu, Pd, Co et Fe divalents. Donnees RMN et IR

A novel fluoride ion colorimetric chemosensor.

A novel phosphonium derivative of naphthalene was synthesized by the reaction of 1,8-dibromomethylnaphthalene with triphenylphosphine, which only showed a distinct color change when treated with fluoride ions.

Urea derivative of calix[4]diquinone: HSO4− ion selective receptor

Abstract Urea derivative of calix[4]diquinone 3 has been synthesized in two steps via urea formation and oxidation of 1 . Anion-ligand interactions were studied by 1 H NMR and electrochemical analysis and showed a good affinity between receptor 3 and HSO 4 − .

Poly(vinyl chloride) membrane cesium ion-selective electrodes based on lipophilic calix[6]arene tetraester derivatives.

New lipophilic tetraesters of calix[6]arene and calix[6]diquinone are investigated as cesium ion-selective ionophores in poly(vinyl chloride) membrane electrodes. For an ion-selective electrode based on calix[6]arene tetraester I, the linear response is 1x10(-6)-1x10(-1) M of Cs(+) concentrations. The selectivity coefficients for cesium ion over alkali, alkaline earth and ammonium ions are determined. The detection limit (log a (Cs (+))=-6.31) and the selectivity coefficient (log k (Cs (+),Rb (+))(pot )=-1.88) are obtained for polymeric membrane electrode containing calix[6]arene tetraester I.

Electrochemistry of a urea-functionalized calix[4]diquinone sulfate-anion selective receptor

Abstract A new class of neutral ligands is synthesized and studied for the binding properties with anions by electrochemical methods. The binding of calix[4]diquinone 1 with HSO 4 − causes a large negative shift of the electrode potentials of the calix[4]diquinone. This novel neutral anion receptor 1 binds anions through hydrogen-bonding and shows high selectivity for HSO 4 − over H 2 PO 4 − , Cl − , and CH 3 CO 2 − . The selectivity of HSO 4 − over H 2 PO 4 − , Cl − , and CH 3 CO 2 − may be attributed to the stronger hydrogen-bonding with the urea moiety, and also with the quinone moiety of 1 receptor, and also the greater compatibility of the cavity of 1 with tetrahedral HSO 4 − .

Anion Recognition by Urea Derivatives of Anthraquinone: Dihydrogen Phosphate Ion Selective Neutral Receptors

Three urea derivatives of anthraquinone were synthesized and they showed a high selectivity for dihydrogen phosphate ions.

Synthesis of Terminal Allenes via a Copper-Catalyzed Decarboxylative Coupling Reaction of Alkynyl Carboxylic Acids

Synthesis of terminal allenes via a copper-catalyzed decarboxylative coupling reaction was developed. Aryl alkynyl carboxylic acid, paraformaldehyde, and dicyclohexylamine were reacted with CuI (20 mol %) in diglyme at 100 °C for 2 h to produce the terminal allene in moderate to good yields. The method showed good functional group tolerance.

A new carboxylate anion selective cobaltocenium calix[4]arene receptor

A new upper-rim cobaltocenium bridged calix[4]arene receptor L is synthesised and by virtue of its unique topology exhibits remarkable carboxylate anion selectivity.

The Molecular Recognition of Amines with Calix[6]arene: Conclusive X-ray and NMR Evidence for Endo and Exo Complex Formation between Calix[6]arene and Amines

Calix[6]arene formed an endo-complex with piperidine and its inclusion properties were investigated by NMR spectroscopy and X-ray crystallography. Especially, the DOSY spectrum showed that piperidine formed a unique complex with calix[6]arene.

Synthesis and Conformational Studies of Lower Rim Cyanomethyl Substituted Calix[4]arenes

The conformational inversion characteristics of calix[4]arenes carrying cyanomethyl groups on the lower rim have been investigated. Complete conversion from a 1,3-alternate to a partial cone conformation was observed for the 1,3-dicyanomethyl ether of calix[4]arene at room temperature, while at higher temperatures further inversion to a 1:1 mixture of partial cone and cone conformers occurred.