New General Models for Evaluating Interactions in Non-Regular Solutions and Adsorption Energies Based on Both Hansen's and Drago's Parameters

This study aims at providing a model for the internal mixing energy of two liquids. The concerned variables are the solute molar volume V (cm3/mol.), the cohesion parameters and the Drago's parameters. The model is based on the following fundamental novelties: The fragmentation of molar cohesive energy ∆Ecoh (kJ/mol) into two distinct categories. Indeed, the dispersive and polar cohesion energies are magnetic and electrical in nature, and the cohesive energy of the chemical bonds (Hydrogen Bond) is due to charge transfer and orbital overlap. The origins of these two categories of energy are different, requiring two different treatments in use. For the first time, a relationship has been established between the cohesive energy from chemical bonds ∆Eh (kJ/mol) and Drago's parameters Ea, Eb, Ca, and Cb (KJ1/ 2mol-1/2). A simple equation has been proposed for the salvation energy of a gaseous solute in a liquid solvent. This equation contains a term for the perturbation energy of the solvent in the presence of the solute, namely the cavity formation energy, and different types of interaction energies between the solvent and the solute at infinite dilution. Based on calorimetric data published, the proposed model is compared with the classic model in terms of the mixing energy. The result shows a clear advantage of the new model over the old or conventional one. Clearly, this new model should provide a new method to determine the interaction parameters or interaction capacities of complex pharmaceutical molecules using a series of simple and well-chosen solvents

Synthèse de nouveaux ligands thiacalixaréniques et étude de leurs propriétés de complexation

8 pagesNational audienceLes perspectives ouvertes par la chimie supramoléculaire sont immenses notamment dans le domaine biomimétique mais aussi à l'interface avec la physique et la science des matériaux. Dans ce contexte nous nous sommes intéressés à une famille de macrocycles synthétiques appelés thiacalixarènes. De nouveaux ligands ont été préparés et leurs propriétés de complexation ont été étudiées vis-à-vis de métaux lourds et de métaux de transition. Ces récepteurs ont été conçus de telle façon qu'ils puissent être fixés sur des supports, leur permettant alors d'être utilisés en phase solide – liquide

Nanomatériaux pour les technologies solaires et l'environnement

Conférence en universitéInternational audienc

Synthesis and Complexation Properties Towards Metal Ions of New Tri-substituted Thiacalix[4]arenes

International audienceNew thiacalix[4]arenes appended with three amide functions have been prepared. Their conformations have been solved thanks to 1H NMR 2D COSY and NOESY. The complexation ability of these ligands towards various metal ions (Cd2+, Pb2+, Pd2+; Ni2+, Hg2+, Hg+, Ag+, Zn2+ and Cu2+) has been investigated by UV-vis absorption and the stoichiometry of the metal-ligand complexes was determine

Studies of morphological optical and electrical properties of the MEH-PPV/azo-calix[4]arene composite layers

International audienceThin films of poly[2-methoxy-5-(20-ethylhexyloxy)-1,4 phenylenevinylene] (MEH-PPV), 5,17-bis(4-nitrophenylazo)-26,28-dihydroxy-25,27-di(ethoxycarbonylmethoxy)-calix[4]arene (azo-calix[4]arene) and MEH-PPV doped azo-calix[4]arene, with 30 wt% and 70 wt% doping ratios, were prepared from chloroform solution by spin coating technique on quartz and ITO substrates. Morphological and optical properties of the samples were investigated by scanning electron microscopy (SEM) and UV-visible spectrophotometry techniques, respectively. Further, the charge carrier transport properties and conduction mechanism of the composite MEH-PPV:azo-calix[4larene thin films based junction were studied by using current-voltage (1-V) characteristics and dielectric spectroscopy technique. I-V characteristic of ITO/MEH-PPV:azo-calix[4]arene/Al devices showed that the space charge limited conduction (SCLC) dominates in the high voltage region. Moreover, frequency dependence of ac conductivity obeys Jonscher's universal power law. Finally, dielectric constant (epsilon'), dielectric loss (epsilon '') and loss tangent (tan delta) were investigated as function of amount of azo-calix[4]arene in the MEH-PPV polymer matrix

Synthesis, characterization and X-Ray structure of N-heterocyclic carbene palladium complexes based on calix[4]arenes : highly catalysts towards suzuki-miyaura cross-coupling reactions

International audienceA new series of calix[4]arene supported N-heterocyclic carbene palladium complexes were developed and fully characterized. A mono-substituted calix[4]arene was prepared through conventional procedures, following with the attachment of imidazolyl derivative groups to compose the precursors of novel NHCs ligands. Undergoing the alkylation with n-butylbromide and corresponding metallation with palladium and pyridine, original complexes were obtained. After a full characterization in solution and solid state, the evaluation of catalytic activity was taken out in Suzuki–Miyaura cross-coupling reactions, which revealed good performances