Acylation of piperidine and morpholine with phenyl benzoates in the mixtures water-2-propanol and water-dioxane

Kinetics of acylation of piperidine and morpholine with 4-nitro- and 2,6-dinitrophenyl benzoates was studied in binary systems water-2-propanol and water-dioxane. Structural and energy characteristics of solvate complexes of morpholine and piperidine with the components of the mixed solvents were calculated. Kinetic regularities of acylation are considered from the viewpoint of specific solvation of amines.     

Reactivity of Benzamide toward Sulfonylation

Russian Journal of Organic Chemistry - The ranges of variation of the rate constant (0.031– 0.153 L·mol–1·s–1), energy of activation (21– 55 kJ/mol), and entropy...     

Optimization of conditions for synthesizing sulfonated hydrazides of benzoic and benzenesulfonic acids

The kinetic relationships of arenesulfonation of benzoic and benzenesulfonic acid hydrazides were studied. Based on the data obtained, the conditions for synthesizing these products were optimized. The synthesis can be performed using aqueous-organic solvents containing 2-propanol, 1,4-dioxane, or tetrahydrofuran as nonaqueous component. The thermal stability of benzenesulfohydrazide and its sulfonation product was compared on the basis of data of gas chromatography–mass spectrometry. The fragmentation pathways of the reactants and target product, sulfonated benzenesulfohydrazide, were suggested.     

Solid solutions of Ba2(In1 ? xAlx)2O5: Structural evolution and hydration processes

Solid solutions of the composition Ba₂(In_{1 − x} Al _x )₂O₅[VO]₁ (0 ≤ x ≤ 0.20) with an incomplete oxygen sublattice were obtained. It was established that, along with an increase in parameter x, there is disordering of oxygen vacant positions and a transition from the structure of brownmillerite to that of defect perovskite. It was demonstrated that the phases under study are characterized by an ability for reversible interaction with water vapors in the temperature range 150–450°C. During this process, proton defects, predominantly in the form of OH⁻ groups, are formed in the oxide structure. We conclude that in a number of solid solutions, the amount of intercalated water declines upon an increase in the aluminum content.     

Reactivity of Tyrosyl–Proline toward Benzoylation in Aqueous 1,4-Dioxane

Russian Journal of Organic Chemistry - The kinetics of the reaction of L-tyrosyl-L-proline (Tyr–Pro) with di- and trinitrophenyl benzoates in aqueous 1,4-dioxane (40 wt % of water) were...     

Comparison of the Reactivities of Tyrosine–Proline-Based Dipeptides toward Acylation with Nitrophenyl Benzoates

Russian Journal of Organic Chemistry - The reactivities of the L-Tyr–L-Pro dipeptide and its analog with a hydroxymethyl group instead of carboxy group in the proline moiety were compared by...     

Quantum-chemical simulation of glycine specific solvation in the solvents water-1,4-dioxane and water-2-propanol

Structural and energy characteristics of the solvatocomplexes of glycine molecular and anionic forms with the components of the solvents water-dioxane and water-2-propanol were calculated by the HF/6–31G method. The results of calculation were compared with kinetic data on the glycine reactions with 3-nitrobenzenesulfonyl chloride and benzoyl chloride that allowed to understand the difference in the effect of composition of these binary solvents on the rate of N-acylation of α-aminoacids.     

Sorption of Acetone and Phenol on Natural Film Coatings of Electrodes of a Bulk Acoustic Wave Piezoelectric Resonator

The sorption–desorption of acetone and phenol on thin-film coatings of electrodes of bulk acoustic wave piezoelectric resonators was studied. Natural materials (bee-glue and beeswax) were used as natural coatings. The sorption activity of the coatings was determined along with their sorption selectivity and stability for the analytical application of modified bulk acoustic wave piezoelectric sensors in the detection of acetone and phenol in the air.     

The synthesis and properties of solid solutions based on Ba<Subscript>4</Subscript>Ca<Subscript>2</Subscript>Nb<Subscript>2</Subscript>O<Subscript>11</Subscript>

(Ba_{1 ? x} Ca _x )₆Nb₂O₁₁ solid solutions were synthesized. The compositions were shown to be single-phase at 0.23 ≤ x ≤ 0.47 and have a double perovskite cubic structure with an incomplete oxygen sublattice. The interaction of solid solutions with water vapor and their electrical properties were studied. In dry atmosphere, these complex oxides were mixed oxygen-hole conductors. In humid atmosphere, they intercalated water and exhibited protonic conductivity. The influence of Ba/Ca isovalent substitution, the dynamics of the oxygen sublattice, and the concentration of intercalated water on the value and contribution of protonic and hole conductivity was analyzed.     

Hydration and proton transport in solid solutions based on Ba<Subscript>2</Subscript>CaWO<Subscript>6</Subscript>

Hydrated alkaline-earth metal tungstates Ba₄Ca_{2 + x} W_{2 ? x} O_{12 ? 2x} with perovskite structure were studied by the thermogravimetry, ¹H NMR, IR, and Raman spectroscopy methods. Electrical conductivity and transfer numbers were measured with varying T, \(p_{O_2 } \) and \(p_{H_2 O} \). The solid solutions are capable of reversibly intercalating water and can exhibit high-temperature proton transport. The localization of protons on oxygen results in the appearance of energetically nonequivalent OH groups; a small fraction of protons are present in the form of H₂O and H₃O⁺.