Thermodynamics of Anion Binding by (Thio)ureido-calix[4]arene Derivatives in Acetonitrile.

In this work, we developed (thio)ureido-calix[4]arene derivatives and thoroughly explored their anion-binding properties in acetonitrile. A series of anions, including important inorganic ones (Cl, HSO , HPO , and HPO ) and several ever-present carboxylates (acetate, benzoate, and fumarate), were studied. All systems were investigated by several methods (NMR, ITC, and UV) used in a synergistic fashion, providing their comprehensive thermodynamic description.

Anion-Binding Properties of Short Linear Homopeptides.

A comprehensive thermodynamic and structural study of the complexation affinities of tetra (), penta (), and hexaphenylalanine () linear peptides towards several inorganic anions in acetonitrile (MeCN) and ,-dimethylformamide (DMF) was carried out. The influence of the chain length on the complexation thermodynamics and structural changes upon anion binding are particularly addressed here. The complexation processes were characterized by means of spectrofluorimetric, H NMR, microcalorimetric, and circular dichroism spectroscopy titrations.

Supramolecular Handshakes: Characterization of Urea-Carboxylate Interactions Within Calixarene Frameworks.

The research of molecular capsules offers high application potential and numerous benefits in various fields. With the aim of forming supramolecular capsules which can be reversibly assembled and dissociated by simple external stimuli, we studied interactions between calixarenes containing urea and carboxylate moieties. To this end two ureido-derivatives of p-tert-butylcalix[4]arene comprising phenylureido-moieties and diacetate-calix[4]arenes were prepared.

Synthesis of aromatic polynitroso compounds: Towards functional azodioxy-linked porous polymers.

The polymerization property of aromatic polynitroso compounds could be used to create azodioxy porous networks with possible application for the adsorption of CO, the main greenhouse gas. Herein, we report the synthesis and characterization of new aromatic polynitroso compounds, with -nitroso groups attached to the triphenylbenzene, triphenylpyridine, triphenyltriazine and triphenylamine moiety. The synthesis of the pyridine-based trinitroso compound was performed by reduction of the corresponding trinitro derivative to -arylhydroxylamine followed by oxidation to the trinitroso product.

Enhancing the Cation-Binding Ability of Fluorescent Calixarene Derivatives: Structural, Thermodynamic, and Computational Studies.

Novel fluorescent calix[4]arene derivatives and were synthesized by introducing phenanthridine moieties at the lower calixarene rim, whereby phenanthridine groups served as fluorescent probes and for cation coordination. To enhance the cation-binding ability of the ligands, besides phenanthridines, tertiary-amide or ester functionalities were also introduced in the cation-binding site. Complexation of the prepared compounds with alkali metal cations in acetonitrile (MeCN), methanol (MeOH), ethanol (EtOH), -dimethylformamide (DMF), and dimethyl sulfoxide (DMSO) was investigated at 25 °C experimentally (UV spectrophotometry, fluorimetry, microcalorimetry, and in the solid state by X-ray crystallography) and by means of computational techniques (classical molecular dynamics and DFT calculations).