This work is devoted to the first demonstration of the synthesis of trichloroacetic acid from chloroform and CO2 in an aqueous solution over TiO2 under irradiation with UV light. The yield of trichloroacetic acid under chosen conditions exceeds 90% with the selectivity to the target product close to 100%. The mechanisms of trichloroacetic acid formation from chloroform and CO2 are considered.

ABSTRACT In the quest for sustainable and efficient chemical processes, the development of advanced catalytic systems capable of selective hydrogenation under mild conditions stands as a pivotal challenge. This study delves into the use of nanotubular phyllosilicates derived through the thermal reduction of transition metals from a precursor matrix as catalysts for the selective hydrogenation of various unsaturated organic compounds. The investigation explores the catalytic properties of these nanotubular phyllosilicates with relatively lower transition metal loadings, providing insights into their potential for industrial applications. Assumptions about the observed catalytic properties of the obtained samples are proposed based on a number of their structural and morphological features. Notably, the study underscores the significant differences in activity between Ni‐ and Co‐containing samples in different processes.

The asymmetric unit of the title compound, C3H4N4O2, contains two coplanar molecules (A and B) completely located on mirror planes. In the crystal, N—H...O, N—H...N, C—H...O and C—H...N hydrogen bonds link the molecules into sheets parallel to (010). There are neither significant π–π nor C—H...π(ring) interactions. Hirshfeld surface analysis indicates that the most important contributions to the crystal packings of molecules A and B are from H...O/O...H (32.4% for A, 30.1% for B), H...N/N...H (28.2%, 31.5%) and H...H (12.3%, 8.0%) interactions.

Copper nanocatalysts doped with palladium deposited on γ-Al2O3 were prepared and used for the hydrogenation of nitrobenzene. The catalysts were obtained by the formation of intermediate metal-complex compounds on the surface of the γ-Al2O3 carrier with their subsequent hydrogenolysis and reduction of the active phases of the catalyst, calcination, and additional treatment with hydrogen. The structure of the catalysts was investigated using the following. low-temperature nitrogen sorption, SEM with EDX, TEM, X-ray fluorescence analysis, XRD, and DRIFTS. DRIFT studies indicate the presence of active phases of catalysts in the form of reduced and divalent palladium and copper. According to DRIFTS-CO data, copper is present in the Cu2+ state in the calcined catalysts Cu/γ-Al2O3_1 and Cu-Pd/γ-Al2O3_1, but it is reduced to Cu+ when the reducing agent, CO, is adsorbed. Palladium in the calcined sample of Cu-Pd/γ-Al2O3_1 is present in two states - Pd2+ and Pd0 (due to the method of preparation of this sample). In the Cu-Pd/γ-Al2O3_2 catalyst, the state of palladium is Pd+. It was found that the metal content on the surface of the particles increases after reduction in hydrogen. The catalyst based on Cu/γ-Al2O3 had low activity, the addition of palladium led to an increase in the activity. Thus, in the presence of the PdCu/γ-Al2O3 catalyst, a 85

The title compounds, C10H9Cl2FN2O3, (I), and C11H12Cl2N2O3, (II), are α,α-dihalo-β-diketone urea derivatives, which contain 4-fluoro­phenyl and p-tolyl groups, respectively. The conformation about the CO—CCl2—CO—Nu (O = keto, Cl2 = di­chloro, u = urea) bond is anti in (I) and gauche in (II). In the crystals of both compounds, O—H⋯O hydrogen bonds generate inversion dimers and the dimers are linked into (100) layers by N—H⋯O hydrogen bonds.

The title compounds, C10H9Cl2FN2O3, (I), and C11H12Cl2N2O3, (II), are α,α-dihalo-β-diketone urea derivatives, which contain 4-fluorophenyl and p-tolyl groups, respectively. The conformation about the CO—CCl2—CO—Nu (O = keto, Cl2 = dichloro, u = urea) bond is anti in (I) and gauche in (II). In the crystals of both compounds, O—H...O hydrogen bonds generate inversion dimers and the dimers are linked into (100) layers by N—H...O hydrogen bonds. The Hirshfeld surface analyses of the crystal structures indicate that the most important contributions for the crystal packings are from H...O/O...H (22.3%), H...H (20.9%), H...Cl/Cl...H (15.6%) and H...C/C...H (10.3%) for (I) and H...H (31.7%), H...O/O...H (25.1%), H...Cl/Cl...H (21.1%) and H...C/C...H (9.5%) for (II).

Catalysts of 1% Pd/TiO2 2 type were prepared via the deposition-precipitation of Pd polyhydroxo complexes followed by reduction with hydrogen at 23 degrees C. These catalysts were found to be active for the selective hydrogenation of m- dinitrobenzene into m-phenylenediamine at 25-50 degrees C and 0.5 MPa H2 2 in a batch reactor.

The cheap non-noble Cu–SiO2-based nanocatalysts are under intensive study in different reactions resulting in useful chemicals, yet their application in environment protection is poorly studied. In the present work, the influence of the Cu loading (3–15 wt%) on the catalytic behavior of Cu/SiO2 materials was first precisely studied in the hydrogenation of hazardous trinitrobenzene to valuable aromatic amines with molecular hydrogen. The catalysts have been synthesized by the method of deposition–precipitation using urea. The catalyst characterization by XRD, TPR-H2, SEM, TEM, and N2 adsorption methods confirmed that they include nanoparticles of the micro-mesoporous chrysocolla-like phase supported in the mesopores of a commercial SiO2 carrier, as well as revealed formation of the highly dispersed CuO phase in the sample with the highest Cu loading. Variation in reaction conditions showed the optimal ones (170 °C, 1.3 MPa H2) resulting in complete trinitrobenzene conversion with a triaminobenzene yield of 65% for the catalyst with a 15% Cu loading, and the best yield of 82% was obtained over the catalyst with 10% Cu calcined at 600 °C. The results show the potential of Cu phyllosilicate-based catalysts for the utilization of trinitroaromatic compounds via catalytic hydrogenation to amines and their possible applications in a remediation treatment system.

Herein, we have isolated new 20-membered macrocycles by the simple condensation of α,α-dihalo-β-oxoaldehydes with diaminofurazan in acetonitrile. The interior and exterior sites of these macrocycles comprise hydrogen and halogen bond...

Nanocomposite materials based on palladium, copper(I) oxide, and magnetite nanoparticles embedded in a nanocellulose matrix by precipitation and coprecipitation methods were obtained in situ and ex situ from solutions of the salts of the corresponding metals. Studies of the characteristics of the resulting composites using Fourier transform IR spectroscopy, X-ray diffraction, SEM, and TEM showed that the encapsulated nanoparticles have an insignificant effect on the morphology and structure of nanofibrillar cellulose. The catalytic properties of the nanocomposites were tested in the hydrogenation of nitrobenzene.

In the crystal of the title compound, mol­ecules are linked to each other and solvent di­methyl­formamide mol­ecules by N—H⋯S, N—H⋯O, C—H⋯O and C—H⋯S hydrogen bonds, forming a three dimensional network.

The overall mol-ecular configuration of the title compound, C12H16N6OS2·C3H7NO, is stabilized in the solid state by intra-molecular C-H⋯N, C-H⋯O, N-H⋯N and N-H⋯O inter-actions, forming S(5) ring motifs. In the crystal, mol-ecules are linked to each other and solvent di-methyl-formamide mol-ecules by N-H⋯S, N-H⋯O, C-H⋯O and C-H⋯S hydrogen bonds, forming a three dimensional network. The phenyl ring of the title compound is disordered over two sites with an occupancy ratio of 0.57 (4):0.43 (4). A Hirshfeld surface analysis was performed to qu-antify the contributions of the different inter-molecular inter-actions, indicating that the most important contributions to the crystal packing are from H⋯H (38.7%), S⋯H / H⋯S (24.0%), C⋯H / H⋯C (18.5%) and N⋯H / H⋯N (9.8%) inter-actions.

The overall molecular configuration of the title compound, C12H16N6OS2 center dot C3H7NO, is stabilized in the solid state by intramolecular C-H center dot center dot center dot N, C-H center dot center dot center dot O, N-H center dot center dot center dot N and N-H center dot center dot center dot O interactions, forming S(5) ring motifs. In the crystal, molecules are linked to each other and solvent dimethylformamide molecules by N-H center dot center dot center dot S, N-H center dot center dot center dot O, C-H center dot center dot center dot O and C-H center dot center dot center dot S hydrogen bonds, forming a three dimensional network. The phenyl ring of the title compound is disordered over two sites with an occupancy ratio of 0.57 (4):0.43 (4). A Hirshfeld surface analysis was performed to quantify the contributions of the different intermolecular interactions, indicating that the most important contributions to the crystal packing are from H center dot center dot center dot H (38.7%), S center dot center dot center dot H / H center dot center dot center dot S (24.0%), C center dot center dot center dot H / H center dot center dot center dot C (18.5%) and N center dot center dot center dot H / H center dot center dot center dot N (9.8%) interactions.

A series of 2-(4-substituted benzoyl)thiazolo[3,2-a]pyridin-4-ium bromides [-OCH3 (1), -H (2), -F (3), -Cl (4)] was obtained by the heterocyclization reaction of the corresponding 2-bromo-1-(4-substituted phenyl)-3,3-diethoxypropan-1-ones with pyridine-2-thiol in dry isopropyl alcohol under reflux for 2 h. The new compounds 1-4 were characterized by elemental analysis, H-1 and C-13 NMR spectroscopy and single crystal X-ray diffraction. Both the negative charge-assisted (S center dot center dot center dot Br-) and normal (S center dot center dot center dot pi) chalcogen bonds were found in the crystal packing of 2-4, whereas one of the hydrogen atoms of an electron-donating -OCH3 group in 1, behaves as a bifurcated hydrogen bond donor centre towards a sulfur atom of the thiazolo ring and an oxygen atom of C=O group of a neighboring molecule leading to the intermolecular hydrogen bonds. The optical properties of 1-4 in DMSO, DMF and MeOH were investigated by UV-vis absorption spectroscopy, with lambda(max) being dependent on the solvent polarity and attached substituents (-OCH3, -H, -F, -Cl) at the para-position of the aromatic moiety.

In the title compound, the dihedral angles between the thiazole ring and its attached chlorophenyl and phenyl rings are 13.12 (14) and 43.79 (14)°, respectively.

Development of novel Cu-based catalysts has become one of the frontiers in the catalytic production of platform chemicals and in environment protection. However, the known methods of their synthesis are too complicated and result in materials that cannot be used instantly as commercial catalysts. In the present work, a novel material has been synthesized by the facile method of deposition–precipitation using thermal hydrolysis of urea. The conditions for Cu phyllosilicate formation have been revealed (molar ratio urea:copper = 10, 92 °C, 8–11 h). The prepared Cu-based materials were studied by TG–DTA, SEM, TEM, XRD, N2 adsorption and TPR-H2 methods, and it was found that the material involves nanoparticles of micro-mesoporous copper phyllosilicate phase with a chrysocolla-like structure inside the pores of a commercial meso-macroporous silica carrier. The chrysocolla-like phase is first shown to be catalytically active in the selective reduction of the nitro-group in trinitrobenzene to an amino-group with molecular hydrogen. Complete conversion of trinitrobenzene with a high yield of amines has been achieved in short time under relatively mild conditions (170 °C, 1.3 MPa) of nitroarene hydrogenation over a copper catalyst.

Supported bimetallic Cu–Fe catalysts revealed high activity and selectivity in isoprenyl acetate hydrogenation to isoprenol under mild reaction conditions (2 MPa H2 and 170 °C). The nature of the carrier has a significant impact on the catalytic properties of Cu–Fe catalysts. The best catalytic properties were found for the 5% Cu–5% Fe/Al2O3 bimetallic catalyst, which provides a 98% isoprenyl acetate conversion in 4 h with the isoprenol selectivity of 82%.

For the first time, the new microwave-assisted method for the synthesis of copper phyllosilicates on a commercial SiO2 carrier was developed. The application of microwave synthesis allowed to decrease the synthesis time from 9 to 6 h compared to the traditional DPU method of preparing chrysocolla. The synthesized catalysts were studied by N2 adsorption, TEM and XRD methods. Catalysts prepared by microwave method are highly effective in the selective hydrogenation of the С≡С bond in 1,4-butynediol to 1,4-butenediol and 2-phenylethinylaniline with a selectivity of 96.5% and 100% at full conversion for 2 and 0.5 h of the reaction, respectively.

The catalytic synthesis of isoprenol by hydrogenation of 3-methylbut-3-en-1-yl acetate on heterogeneous bimetallic Cu-Pt catalysts was carried out for the first time. The best selectivity of isoprenol (76%) was obtained on the 5%Cu–1%Pt/SiO2 catalyst with a full ester conversion in 6 h of the reaction.