Layered perovskite-type oxides A2Ln2Ti3O10(A = Li, Na, K; Ln = La, Nd) prepared by solid-phase synthesis and their hydrated forms were characterized by the methods of TGA, XRD, and by UV-Vis...

Novel 1,2,4-thiadiazole derivatives as potent neuroprotectors were synthesized and identified. Their ability to inhibit the glutamate stimulated Ca²⁺ uptake was investigated. The solubility of thiadiazoles was measured in a buffer solution (pH 7.4) at 298 K. The distribution coefficients in 1-octanol/buffer (pH 7.4) and 1-hexane/buffer (pH 7.4) immiscible phases as model systems imitating the gastrointestinal tract epithelium and the blood–brain barrier were determined. Permeation experiments the new Permeapad™ barrier using Franz diffusion cells were conducted and the apparent permeability coefficients were obtained. The influence of the compound structure on the physicochemical properties determining the bioavailability of drug-like substances was revealed. Solubility–permeability interplay has been assessed to evaluate potential bioavailability of the compounds studied.

The behavior of perovskite-like NaNdTiO₄ complex oxide in acid aqueous solutions was studied. By the X-ray and thermogravimetry analyses the instability of NaNdTiO₄ in aqueous solutions was found, which is determined by the sodium cation exchange for protons and by water molecules intercalation into the interlayer space of the crystal structure. The proton-containing layered oxides HNdTiO₄ and H _x Na_1−x NdTiO₄·yH₂O were obtained (1 < x < 0.64, 0 < y < 0.47). The structure of the H_0.73Na_0.27NdTiO₄·0.3H₂O compound was refined.

A series of hybrid inorganic–organic niobates HCa₂Nb₃O₁₀×ROH, containing n-alkoxy groups of primary alcohols (R = Me, Et, Pr, Bu, Hx, and Dc) grafted in the interlayer space, has been studied for the first time in relation to photocatalytic hydrogen generation from a model 1 mol % aqueous solution of methanol under ultraviolet irradiation. Photocatalytic activity was measured both for bare samples and for their composites with Pt nanoparticles as a cocatalyst. The advanced measurement scheme allowed monitoring the volume concentration of a sample in a suspension during the experiment, its pH, and possible exfoliation of layered compounds into nanolayers. In the series of n-alkoxy derivatives, the maximum rate of hydrogen evolution was achieved over a Pt-loaded ethoxy derivative HCa₂Nb₃O₁₀×EtOH/Pt. Its apparent quantum efficiency of 20.6% in the 220–350 nm range was found not to be caused by changes in the light absorption region or specific surface area upon ethanol grafting. Moreover, the amounts of hydrogen released during the measurements significantly exceeded those of interlayer organic components, indicating that hydrogen is generated from the reaction solution rather than from the hybrid material.