N-Benzhydrylformamides are pharmacologically active compounds with anticonvulsant, enzyme-inducing, antihypoxic, and other types of biological activity. The conformational behavior of benzhydrylformamides is determined to a great extent by the presence of substituents at the nitrogen atom and in the ortho-position(s) of the diphenylmethane moiety. Particularly, the NMR spectra of these compounds often contain two sets of signals originating from different orientations of the formyl group. With the use of the dynamic NMR method and DFT calculations, we investigated the internal rotations of aromatic and formyl fragments and estimated the corresponding rotational barriers in N-benzhydrylformamide (BHFA), N-methyl-N-benzhydrylformamide (BHFA-NMe), and in a series of ortho-halogen-substituted N-benzhydrylformamides. It was found that the DFT method at M06-2X/6-311+G* level of theory satisfactorily reproduces the experimental barrier $\Delta G_{298}^{\ne }$(Formyl) of the formyl group rotation in BHFA-NMe. In BHFA, BHFA-NMe, and in the ortho-halogen derivatives, the calculated $\Delta G_{298}^{\ne }$(Formyl) values are close to each other and lie within 20–23 kcal/mol. On the other hand, the ortho-substituents significantly hinder the rotation of aryl fragment with $\Delta G_{298}^{\ne }$(Aryl) values varying from 2.5 kcal/mol in BHFA to 9.8 kcal/mol in ortho-iodo-N-benzhydrylformamide.

In this work, composite materials were obtained for the first time using various methods and the dependences of the resulting surface morphologies were investigated. This involves modifying the surface with cucurbit[n]urils, which are highly promising macrocyclic compounds. The process includes applying cucurbit[6]uril to the hydroxyapatite surface in water using different modification techniques. The first method involved precipitating a dispersion of CB[6] in undissolved form in water. The second method involved using fully dissolved CB[6] in deionized water, after which the composite materials were dried to constant weight. The third method involved several steps: first, CB[6] was dissolved in deionized water, then, upon heating, a dispersion of CB[6] was formed on the surface of HA. The fourth method involved using ultrasonic treatment. All four methods yielded materials with different surface morphologies, which were studied and characterized using techniques such as infrared (IR) spectroscopy and scanning electron microscopy (SEM). Based on these results, it is possible to vary the properties and surface morphology of the obtained materials. Depending on the method of applying CB[6] to the surface and inside the HA scaffold, it is possible to adjust the composition and structure of the target composite materials. The methods for applying CB[6] to the hydroxyapatite surface enhance its versatility and compatibility with the body’s environment, which is crucial for developing new functional composite materials. This includes leveraging supramolecular systems based on the CB[n] family. The obtained results can be used to model the processes of obtaining biocomposite materials, as well as to predict the properties of future materials with biological activity.

This study outlines a method for preparing a complex involving glycoluril and melamine (GU-ME). The structure of the resultant complex was analyzed using IR and NMR spectroscopy. In the subsequent phase, the polymer GUMEFA was derived from the resultant complex, employing hydroxyethylidene diphosphonic acid (HEDP) as a sustainable plasticizer, with a proposed chemical mechanism for its formation. The molecular weight of the resulting GUMEFA was analyzed, and the formation chemistry was proposed. GUMEFA was characterized, and its free formaldehyde and methylol group contents were investigated. It was observed that GUMEFA prepared with HEDP contained approximately 1.15–1.34 wt.% free formaldehyde and 1.56–0.54 wt.% methylol groups. These findings provide valuable insights for developing resins of different compositions and applications, thereby paving the way for producing composite materials with tailored properties.

For the first time, neodymium nickel manganites NdNa₂NiMnO₅ and NdK₂NiMnO₅ were synthesized via the solid-state interaction method, and they crystallize in a cubic system. Using experimental dynamic calorimetry in the temperature range of 298.15–673 K, the temperature dependences of the heat capacity of NdNa₂NiMnO₅ and NdK₂NiMnO₅ were studied. At 423 K, both compounds exhibited anomalous heat capacity jumps on the C⁰_p~f(T) dependency, likely corresponding to second-order phase transitions. Considering the phase transition temperatures, equations for the temperature dependence of heat capacity were derived, accurately describing the experimental data. Based on the experimental C⁰_p(T) data and calculated S⁰ (298.15) values, temperature dependences of C⁰_p(T) and the thermodynamic functions S⁰(T), H°(T)–H⁰(298.15), and Φ^xx(T) were determined for the studied compounds within the 298.15–673 K range. The analysis of electrophysical data confirmed the semiconducting and metallic nature of the conductivity, as well as identified the band gap and activation energy of conductivity. These results are valuable for the application of these materials in electronics and for controlling conductivity.

The article presents the results of synthesis, radiographic and thermodynamic studies of the cupratevanadato-manganite compound LaLi ₂ CuVMnO _7.5 . Using ceramic technology, a new cuprate-vanadatomanganite LaLi ₂ CuVMnO _7.5 was synthesized. The structure was analyzed by X-ray diffraction (XRD). The Xray images were indicated by the analytical method. Pycnometric densities were determined in glass pycnometers with a volume of 1 ml. 3 times and the data were averaged. The results show that LaLi ₂ CuVMnO _7.5 crystallizes in cubic syngony with lattice parameters: а=14,01 ± 0,01 Å; Z=4; Vo=2747,18 ± 0,03 Å ^³ ; V _oun . _cell. =686,87 ± 0,87 ų, ρ _x-ray .=4,27 and ρ _picn .=4,26 ± 0,005 g/sm³. The temperature dependence of the heat capacity of LaLi ₂ CuVMnO _7.5 was studied using a serial IT-C-400 calorimeter in the range of 298.15-673 K. The calibration of the device was carried out based on determining the thermal conductivity of the heat meter. For this purpose, experiments were conducted using a copper sample and an empty ampoule. At each temperature (in increments of 25 K), five parallel experiments were performed, and the results were processed using methods of mathematical statistics by calculating the mean value. The performance of the device was verified by determining the heat capacity of α-Al ₂ O ₃ . Based on experimental data, equations describing the temperature dependence were derived. It was established that LaLi ₂ CuVMnO _7.5 undergoes a λ-shaped effect at 348 K, which is likely related to a second-order phase transition. Using a calculation method, the values of the thermodynamic functions H°(T)-H°(298,15), S°(T), Ф**(Т) for the studied cuprate-vanadate-manganite were evaluated. The research results are important for further studies of the electrophysical properties of this compound and are also of interest for predicting valuable physicochemical properties and the certification of the laboratory prototype of LaLi ₂ CuVMnO _7.5 .