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The leaves of Passiflora ligularis Juss (known as sweet granadilla for its edible fruits) are a crop byproduct that is discarded. With the aim of contributing to give value-added products from these crop by-side products to farmers of Colombian Andes, we carried out a 1H-NMR-metabolomics analysis of polar extracts from leaves collected in three locations and stored in two conditions in order to identify glucosyl-hydrolase inhibitors. Variations in the metabolic profile and the bioactivity among samples were analyzed by orthogonal partial least square discriminant analysis. Thus, 1H-NMR signals related to polyphenolic compounds, saponins, and amino acids were correlated with higher inhibitory activities. Moreover, a targeted NMR and HPLC-MS/MS analysis allowed the identification of 14 polyphenolic compounds and the structural characterization of a new triterpenoid saponin, ligularoside A. The measurements of IC50 values for α-amylase and α-glycosidase inhibitors allowed the identification of quercetin-3-O-β-glucoside, kaempferol-3-O-β-glucoside, and ligularoside A as the most active compounds. These results suggest that P. ligularis leaves are a source of glucosyl-hydrolase inhibitors and lay the foundation for exploring additional applications.

3-Amino-5-phenyl-1,3-thiazolidin-2-iminium bromide was synthesized for the first time by reaction of (1,2-dibromoethyl)benzene with thiosemicarbazide hydrochloride. Its condensation with aromatic aldehydes afforded the corresponding Schiff bases. The structure of the isolated compounds was confirmed by 1H and 13C NMR spectroscopy.

The reaction of 5-acetyl-4-aryl-6-hydroxy-3,6-dimethyl-4,5,6,7-tetrahydroindazoles p-toluenesulfonyl chloride in boiling acetone in the presence of triethylamine was found to occur in a completely regioselective with the exclusive formation of 5-acetyl-4-aryl-6-hydroxy-3,6-dimethyl-1-(4-methylbenzenesulfonyl)-4,5,6,7-tetrahydroindazoles. The experimental results were confirmed by quantum chemical calculations. In silico biological activity evaluation of the synthesized compounds was performed.

Biological active compounds on the basis of 3-amino-5-phenylthiazolidin-2-iminium bromide were synthesized, and their biological activity was studied. The structures of the synthesized compounds were confirmed by 1H and 13C NMR spectroscopy and X-ray diffraction analysis.

1-Aryl-3-(4-bromophenyl)-4,4-dichloro-1,2-diazabuta-1,3- dienes were synthesized via copper-catalyzed reaction of 4-bromobenzaldehyde arylhydrazones with CCl4. X-ray diffraction analysis revealed non-covalent Cl···Br interactions in the crystalline state and formation of 3D supramolecular framework; DFT calculations and topological analysis of the electron density distribution within the framework of Bader's theory (QTAIM method) confirmed these observations. Theoretical calculations showed that highly polarizable dichlorodiazadiene unit is capable of acting as a relatively strong halogen bond donor.

The nanostructuring of hydroxyl-substituted diazacrown-ether (DC) by silver nanoparticles was obtained by green synthesis method in order to increase the antibacterial activity of silver nanoparticles. The synthesized DC, nanoparticles, and nanosupramolecular complex (Ag@DC) were studied by TEM, powder-XRD, and NMR, IR, and UV spectroscopy methods. The Ag@DC nanostructures were uniform and their sizes ranged from 8 to 18 nm. IR and UV spectra revealed the noncovalent formation of the nanosupramolecular complex. The antibacterial activities of the prepared active agents were investigated on gram-positive and gram-negative bacteria by twofold microdilution method. Ultrastructural study by TEM was performed on \textit{E. coli} BDU12 after treatment with Ag@DC. The results showed the improvement of the antibacterial action of Ag@DC compared to silver nanoparticles (E. coli BDU12 - 32 times, A. baumannii BDU32 - 16 times, K. pneumoniae BDU44 and P. aeruginosa BDU49 - 4 times, S. aureus BDU23 - 512 times). Chelating by DC significantly improved the antibacterial effects of the silver nanoparticles on gram-positive and gram-negative bacteria due to the ionophoric behavior of the crown ethers.

New tetrahydroisoquinoline-5,7-dicarbonitrile derivatives have been synthesized by piperazine hydrate-catalyzed reaction of acetoacetanilide with 2-(1-arylethylidene)malononitriles (Knoevenagel condensation products of acetophenones and malononitrile) in aqueous ethanol at room temperature. The product structure was confirmed by NMR spectra and X-ray analysis of 1,6-diamino-4a-methyl-3-oxo-2,8-diphenyl-2,3,4,4a-tetrahydroisoquinoline-5,7-dicarbonitrile.

Cobalt oxide nanoparticles were synthesized using a facile and convenient sonochemical method, followed by a calcination process. For the synthesis, cobalt nitrate, and sodium borohydride w...

Functionalized graphene nanoplatelets (FGNPs) were synthesized through oxidative chlorophosphorylation (OxCh) reaction of graphite and subsequent hydrolysis of obtained chlorophosphonated graphite. Then FGNPs were used as a nanoscale filler to fabricate FGNPs/modified polybutadiene (MPB) hybrid composite (FGNPs/MPB). Fourier-transform infrared spectroscopy found that FGNPs have phosphonate functional groups and FGNPs/MPB has phosphonate and phosphate functional groups. X-ray diffraction showed that the thickness of FGNPs is 13.53 nm and the number of their layers is equal to 40, which are less than graphite’s thickness (37.08) and layers (111). FGNPs show high conductivity and dielectric permittivity than graphite, while FGNPs/MPB has improved electric properties than MPB without filler. Thermal properties of FGNPs/MPB also improve due to the fact that FGNPs achieve a high degree of dispersion with less agglomeration. As observed in the scanning electron microscope images, FGNPs/MPB displays a two-phase morphology with an MPB continuous phase and a dispersed FGNPs phase.

In the crystal of the title salt, the cations and anions are linked via N—H⋯Br hydrogen bonds. In the 1H NMR spectra of this compound, the NH iminium protons are observed at δ = 10.46 p.p.m., which confirms the strong charge-assisted hydrogen bonding (CAHB) in the =HN+—H⋯Br− synthon., The title salt, C16H15ClN3S+·Br−, is isotypic with (E)-3-[(4-fluoro­benzyl­idene)amino]-5-phenyl­thia­zolidin-2-iminium bromide [Khalilov et al. (2019 ▸). Acta Cryst. E75, 662–666]. In the cation of the title salt, the atoms of the phenyl ring attached to the central thia­zolidine ring and the atom joining the thia­zolidine ring to the benzene ring are disordered over two sets of sites with occupancies of 0.570 (3) and 0.430 (3). The major and minor components of the disordered thia­zolidine ring adopt slightly distorted envelope conformations, with the C atom bearing the phenyl ring as the flap atom. In the crystal, centrosymmetrically related cations and anions are linked into dimeric units via N—H⋯Br hydrogen bonds, which are further connected by weak C—H⋯Br contacts into chains parallel to the a axis. Furthermore, not existing in the earlier report of (E)-3-[(4-fluoro­benzyl­idene)amino]-5-phenyl­thia­zolidin-2-iminium bromide, C—H⋯π inter­actions and π–π stacking inter­actions [centroid-to-centroid distance = 3.897 (2) Å] between the major components of the disordered phenyl ring contribute to the stabilization of the mol­ecular packing. Hirshfeld surface analysis and two-dimensional fingerprint plots indicate that the most important contributions for the crystal packing are from H⋯H (30.5%), Br⋯H/H⋯Br (21.2%), C⋯H/H⋯C (19.2%), Cl⋯H/H⋯Cl (13.0%) and S⋯H/H⋯S (5.0%) inter­actions.

Surface functionalization is an important chemical task that allows to manipulate graphite’s physical and chemical properties. It helps improve graphite’s processability, giving it new prop...

Michael addition of various substituted benzylidene- and thiophen-2-ylmethylidenemalononitriles with acetoacetanilide gave the corresponding 5-acetyl-2-amino-4-aryl(hetaryl)-6-oxo-1-phenyl-1,4,5,6-tetrahydropyridine-3-carbonitriles. Treatment of the latter with ethylenediamine in boiling methanol resulted in their rearrangement with elimination of the acetyl group and formation of 2-anilino-4-aryl(hetaryl)-6-oxo-1,4,5,6-tetrahydropyridine-3-carbonitriles. The product structure was proved by NMR spectroscopy and X-ray analysis.

As a result of triple condensation of malonodinitrile with benzaldehyde and ethyl 2-chloro-3-oxobutanoate a compound with 3-azabicyclo[3.1.0]hexane framework is formed whose crystal structure is determined by X-ray crystallography. In the crystal structure a layered character of the molecular packing is found. Molecules are linked in the layer by H bonds of N-H…O=C and C-H…O=C types and also a large number of atom-atom contacts whose energy corresponds to potential wells.

A detailed study of the dispersion of magnetite (Fe3O4) nanoparticles in the polypropylene (PP) matrix, the degree of coagulation, and the dependence of magnetic properties of PP + Fe3O4nanocomposites on the size of nanoparticles is reported. The size distribution of nanoparticles in polymer matrix and morphology of the nanocomposites were studied by the means of scanning electron microscope (JEOL JSM-7600 F) and atomic force microscopy (NT-MDT). It was found that when the Fe3O4nanoparticles are introduced into the PP matrix, their coagulation takes place. The increase in the size of the Fe3O4nanoparticles depends on their volume content in the polymer matrix, the viscosity of polymer, mixing time, and so on. The magnetic properties of PP + Fe3O4nanocomposites were experimentally and theoretically studied. It was found that the magnetic hysteresis parameters of the nanocomposites directly depend on the size and concentration of the Fe3O4nanoparticles in the matrix. Theoretical calculations were compared with experimental results obtained from M( H) measurements. Discrepancy between theoretical and experimental magnetic values have been explained.

Novel halogenated aromatic dichlorodiazadienes were prepared via copper-mediated oxidative coupling between the corresponding hydrazones and CCl4. These rare azo-dyes were characterized using 1H and 13C NMR techniques and X-ray diffraction analysis for five halogenated dichlorodiazadienes. Multiple non-covalent halogen&middot, &middot, halogen interactions were detected in the solid state and studied by DFT calculations and topological analysis of the electron density distribution within the framework of Bader&rsquo, s theory (QTAIM method). Theoretical studies demonstrated that non-covalent halogen&middot, halogen interactions play crucial role in self-assembly of highly polarizable dichlorodiazadienes. Thus, halogen bonding can dictate a packing preference in the solid state for this class of dichloro-substituted heterodienes, which could be a convenient tool for a fine tuning of the properties of this novel class of dyes.

Banana passion fruit of the Passiflora genus, are commercially cultivated on a small to medium scale, mainly as edible fruits or as components of traditional herbal medicines. This subgenus comprises several species and hybrid specimens that grow readily in the wild. Due to their taxonomical complexity, many of these species have recently been reclassified (Ocampo Perez and Coppens d’Eeckenbrugge, 2017), and their chemical profile has still to be determined. In this study, an 1H NMR-based platform was applied to the chemical profiling of seven wild species of the Passiflora subgenus, and UHPLC-DAD-MS was additionally used for the identification of phenolic compounds. A total of 59 compounds were detected including 26 O- and C-glycosidated flavonoids and polyphenols, nine organic acids, seven amino acids, GABA, sucrose, glucose, myo-inositol, and five other non-identified compounds. Two of the identified compounds are the previously undescribed C-glycosyl flavonoids, apigenin-4′-O-β-glucopyranosyl, 8-C-β-(6″acetyl)-glucopyranoside and apigenin-4-O-β-glucopyranosyl-8-C-β-neohesperidoside. These C-glycosyl flavonoids were isolated to confirm their proposed structures by NMR and LCMS analysis. The PCA score plots obtained from the 1H NMR data of the studied Passiflora samples showed P. cumbalensis and P. uribei as the species with the most distinguishable chemical profile. In addition, a correlation analysis using OPLS-DA was conducted between 1H-NMR data and the quorum quenching activity (QQ) of Chromobacterium violaceum ATCC 31532. This analysis revealed P. lehmannii, and P. uribei extracts to be the most active, and apigenin-4′-O-β-glucopyranosyl, 8-C-β-(6″acetyl)-glucopyranoside and apigenin-4-O-β-glucopyranosyl-8-C-β-neohesperidoside were identified as possibly responsible for the QQ activity. To confirm this, QQ activity of both compounds was tested against C. violaceum ATCC 3153. An inhibition of violacein production of 0.135 mM (100 μg/mL) and 0.472 mM (300 μg/mL) was observed for apigenin-4′-O-β-glucopyranosyl,8-C-β-(6″acetyl)-glucopyranoside and apigenin-4-O-β-glucopyranosyl-8-C-β-neohesperidoside respectively, while bacterial growth was unaffected in both cases. Furthermore, both compounds showed the ability to inhibit the production of the toxoflavin of the phytopathogen Burkholderia glumae ATCC 33617.

The molecular and crystal structures of 1-(4-fluorophenyl)-1,4-dihydro-1H-tetrazole-5-thione (I) and its complex with cadmium(II) (II) are studied by single crystal XRD. Free ligand I is thione; it has a nonplanar structure (the torsion angle between the tetrazole and benzene rings is 54.99(7)°) and forms H-bonded centrosymmetric dimers via two N–H…S hydrogen bonds in the crystal. The dimers contain a central planar eight-membered {S=C–N–H…S=C–N–H…} ring. Complex II has a chain structure with the composition [(C7H4N4FS)2Cd]n. The environment of the Cd(II) atom consists of two nitrogen atoms and two sulfur atoms from four ligands I and represents a distorted tetrahedron. When complex II forms, ligand I converts into the thiol form. Infinite 1D chains contain eight-membered {←S=C–N–Cd←S=C–N–Cd} rings in a chair conformation. The chains in the crystal are arranged in layers parallel to the (101) plane due to secondary intermolecular F…F and π–π-stacking interactions.

We report a novel three-component condensation of benzalacetophenone, ethyl acetoacetate, and malonodinitrile in a 1:1:1 molar ratio respectively, involving an equimolar amount of morpholine acetate to form ethyl-4,6(R,S)-diphenyl-2-dicyanomethylenecyclohex-3-ene-1(R,S)-carboxylate whose crystal structure is determined by single crystal XRD. The intermolecular interaction is analyzed using an atomatom potential model, and infinite chains of energetically tightly coupled molecules in the crystal structure are identified and described. A weak hydrogen bond of the CAr–H…O type is found.

Schiff base condensation of 2-nitrobenzaldehyde with (para-substituted phenyl)hydrazine in the presence of CH3COONa in EtOH at 80 °C produces (E)-1-(para-substituted phenyl)-2-(2-nitrobenzylidene)hydrazines [−OCH3 (1), −CH3 (2), −H (3), −Br (4), −Cl (5), −F (6)]. CuCl catalyzed olefination of 1−6 with CCl4 in the presence of tetramethylethylenediamine (TMEDA) in DMSO leads to (E)-1-(2,2-dichloro-1-(2-nitrophenyl)vinyl)-2-(para-substituted phenyl)-diazenes [−OCH3 (7), −CH3 (8), −H (9), −Br (10), −Cl (11), −F (12)], respectively. 1–12 were characterized by 1H and 13C NMR spectroscopies, ESI-MS, elemental and X-ray diffraction (for 8, 9 and 12) analysis. The single crystal X-ray analysis of 8, 9 and 12 evidence the intramolecular N⋯Cl pnicogen bonds which is significantly strengthened in view of the planarity of the four atoms involved in the 1,4-membered synthon. The intermolecular halogen and hydrogen bonds also contribute to stabilize the crystal structures of 8, 9 and 12. In DMSO solution 1–12 exist in the E-isomeric form, which stabilized by inter- and intramolecular noncovalent interactions. Solvatochromic behavior on UV–vis absorption spectra of azo dyes 7–12 were studied in CH2Cl2, DMF and MeOH, which λmax is dependent on the attached substituents at para- position of aromatic moiety.

The efficiency of (2E,4E)-1-(2-hydroxy-5-methylphenyl)-5-phenyl-2,4-pentadiene-1-one (1), (2E)-3-[2-(allyloxy)-5-bromophenyl]-1-(2-hydroxy-5-methylphenyl)-2-propen-1-one (2), (E)-4-methyl-2-(3-methyl-4-styryl-4.5-dihydrobenzoisoxazol-6-yl)phenol (3) and 2-{4-[2-(allyloxy)-5-bromophenyl]-3-methyl-4.5-dihydro-1.2-benzisoxazol-6-yl}-4-methylphenol (4) as corrosion inhibitors have been studied by weight loss measurements for St-3 mild steel specimen in brine-kerosene mixture. The corrosion rates of St‑3 steel decreased with increase in concentration of the studied compounds.

The structure and dielectric measurements made on the nanocomposites based on PP polypropylen and TiO2 nanoparticles are reported in this paper. It has been defined that, the incorporation of TiO2 ...

The new nickel coordination polymer [Ni(HL1) (CH3OH)2]n (1) and co-crystal H3L1∙DMF (2) were obtained by reaction of NiCl2·2H2O with 2-(2-(1,3-dioxo-1-(phenylamino)butan-2-ylidene) hydrazineyl)benzoic acid (H3L1) in the presence and absence of triethylamine, respectively, in a mixture of methanol and dimethylformamide (DMF) (20:1, v/v). Reaction of CuCl2·2H2O with H3L1 in the presence of 2,2'-(methylazanediyl)bis (ethan-1-ol) (HR) in methanol yields [Cu(HR)2(H2L1)2] (3), whereas treatment of this copper salt with sodium 2-(2-(1,3-dioxo-1-(phenylamino)butan-2-ylidene)hydrazineyl)benzenesulfonate (NaH2L2) in a mixture of acetone and water (10:1, v/v) produces [Cu(HL2) (H2O)2]∙2(H2O)∙{(CH3)2C = O} (4). Compounds 1−4 were characterized by IR and ESI-MS spectroscopies, elemental and X-ray crystal structural analyses, and tested as catalyst for the Henry reaction of aliphatic and aromatic aldehydes with nitroethane in different solvents such as acetonitrile, methanol or water. Good yields (up to 87%) and diasteroselectivities (syn/anti 77:23) were observed in the reactions catalyzed by 3 in water.

Two known lanthanide complexes, [KLa(HL 1 ) 2 {(CH 3 ) 2 NCHO} 2 (H 2 O) 3 ] ( 1 ) and [Sm(H 2 O) 9 ]( E -H 2 L 2 ) 3 ·2H 2 O ( 2 ) were prepared by reaction of lanthanum(III) and samarium(III) nitrates with potassium 3-(2-(2,4-dioxopentan-3-ylidene)hydrazinyl)-2-hydroxy-5-nitrobenzenesulfonate (KH 2 L 1 ) and potassium ( E,Z )-5-chloro-3-(2-(1,3-dioxo-1-phenylbutan-2-ylidene)hydrazinyl)-2-hydroxybenzenesulfonate (KH 2 L 2 ), respectively. Catalytic activities of 1 and 2 were evaluated in the cyanosilylation of aldehydes with trimethylsilyl cyanide in different solvents such as tetrahydrofuran, dichloromethane or methanol. Complex 1 was found to be efficient catalyst for the cyanosilylation reaction in methanol medium at room temperature, producing cyanohydrin trimethylsilyl ethers with good yields (76–99%).

Different solids consisting in hydrous zirconia were synthesized by the water in oil microemulsion technique (ME series). For comparative purposes, diverse solids were also obtained by the conventional sol-gel method (P-series). The solids were tested for liquid-phase selective hydrogenation of furfural to furfuryl alcohol, using propan-2-ol as the hydrogen donor (Meerwein–Ponndorf–Verley process). The best results corresponded to catalysts calcined at 200 °C which consisted in amorphous solids with surface areas of ca 200 m2/g. The presence of some surfactant remaining from the synthetic process in solids obtained through the microemulsion technique favored selectivity to furfuryl alcohol with values ≥98%. Results were explained by the steric hindrance of furfural by the surfactant molecules in micelles thus favoring the interaction of the substrate with hydroxyl groups in hydrous zirconia through the C O group. Application of microwave irradiation accelerated the reaction (15–30 times) as compared to conventional heating.

In this article, we report about the synthesis of magnetic polymer nanocomposites comprising magnetite (Fe3O4) nanoparticles in a polyethylene (PE) matrix. The structure and composition of nanocomposite materials using scanning electron microscopy and atomic force microscopy have been studied. It has been defined that the agglomeration of nanoparticles does not occur, by increasing the volume content of nanoparticles up to 60%, and Fe3O4 nanoparticles act out like single-domain particles. It has also been revealed that nanocomposites based on PE + Fe3O4 with nanoparticle content in a polymer matrix up to 60% behave like superparamagnetic particles. It has also been revealed that the PE + Fe3O4-based nanocomposites effectively absorb the electromagnetic waves in the high frequency range of 0.1–30 GHz. It is shown that the properties of ultrahigh electromagnetic waves can be varied by varying the thickness of the nanocomposite films and the concentration of Fe3O4 nanoparticles.

Convenient and environmentally friendly synthesis of Co9S8/PVA, CoxSy/EG and CoxSy/3-MPA nanocomposites were carried out in the presence of ultrasonic irradiation by the liquid phase synthesis of the sonochemical method. For the synthesis, cobalt acetate tetrahydrate [Co(CH3COO)2·4H2O] and sodium sulfide (Na2S·9H2O) were used as a cobalt and sulfur precursor, respectively. Polyvinyl alcohol (PVA), ethylene glycol (EG) and 3-mercaptopropionic acid (3-MPA) were used as a capping agent and surfactant. The structural, optical properties and morphology of nanocomposites were characterized using X-ray diffractometer (XRD), Ultraviolet/Visible Spectroscopy (UV–Vis), Fourier-transform infrared spectroscopy (FTIR) and scanning electron microscopy (SEM). The optical band gap of Co9S8/PVA is 1.81 eV and for CoxSy/EG is 2.42 eV, where the direct band gap of bulk cobalt sulfide is (0.78–0.9 eV). The wide band gap indicates that synthesised nanocomposites can be used in the fabrication of optical and photonic devices. The growth mechanisms of the Co9S8, CoS2 and Co3S4 nanoparticles were discussed by the reactions. The effects of sonication time and annealing temperature on the properties of the nanoparticles have been studied in detail.

Reaction of bis(4-hydrazinylphenyl)methane with 4-substitutedbenzaldehyde in the presence of CH3COONa in EtOH at 80 °C yields bis(4-((E)-2-(4-substitutedbenzylidene)hydrazinyl)phenyl) methane [−N(CH3)2 1, −F 2, −Cl 3, −NO2 4], which subsequently in the presence of CCl4, CuCl and tetramethylethylenediamine in DMSO undergoes Cu-catalyzed olefination products, bis(4-((E)-(2,2-dichloro-1-(4-substitutedphenyl)vinyl)diazenyl)phenyl)methane [−N(CH3)2 5, −F 6, −Cl 7, −NO2 8], respectively. All compounds were characterized by IR (for 1–4), 1H and 13C NMR spectroscopies, elemental and X-ray diffraction analysis (for 7 and 8). No only intermolecular hydrogen and intramolecular N⋯Cl tetrel bonds, but also the Cl⋯Cl and Cl⋯O types of halogen binding were found in the structures of 7 and 8, respectively. The collected data confirm that bis-azodyes 5–8 exist in DMSO solution and in solid state exclusively in the E-isomeric form, being stabilized by noncovalent interactions. Solvent effects on the UV–vis absorption spectra of 5−8 were studied in CH2Cl2, DMF and EtOH, which λmax is dependent on the type of substituents attached para-position of aromatic moiety.

C14H17NO3, monoclinic, P21/n (no. 14), a = 11.1445(7) Å, b = 8.5442(5) Å, c = 14.2503(8) Å, β = 97.5684(11)°, V = 1345.10(14) Å3, Z = 4, R gt(F) = 0.0668, wR ref(F 2) = 0.1680, T = 296(2) K.

Ethyl 3,3,5,5-tetracyano-2-hydroxy-2-methyl-4,6-diphenylcyclohexane-1-carboxylate was synthesized for the first time by three-component condensation of benzaldehyde with ethyl acetoacetate and malononitrile in the presence of trichloroacetic acid. The product structure was proved by X-ray analysis.

The new mononuclear nickel(II) complexes [Ni(HL 1 )(H 2 O) 2 (CH 3 OH)] ( 1 , NaH 2 L 1 = sodium ( Z )-2-(2-(1,3-dioxo-1-(phenylamino)butan-2-ylidene)hydrazinyl)benzenesulfonate) and [Ni(H 2 L 2 ) 2 (H 2 O) 4 ] [(CH 3 ) 2 S O) 2 ] ( 2 , H 3 L 2 = (Z)-2-(2-(1,3-dioxo-1-(phenylamino)butan-2-ylidene)hydrazinyl)benzoic acid) were synthesized and characterized by IR and ESI-MS spectroscopies, elemental and X-ray crystal structural analyses. Both compounds 1 and 2 act as homogenous catalysts for the diastereoselective nitroaldol (Henry) reaction of aliphatic and aromatic aldehydes with nitroethane in different solvents such as acetonitrile, methanol or water. Complex 1 was found to be the more efficient catalyst for the Henry reaction in aqueous medium, providing β-nitroalcohols with good yields (67–82%) and diastereoselectivities ( syn/anti 59:41–70:30).

β-NiS nanoparticles (NPs) grown through SILAR technique into functionalized nitrile butadiene rubber (FNBR) were used for the synthesis of CuS-NiS/FNBR and Cu1.8S-Ni3S4/FNBR nanocomposites (NCs). The evaluated band gap decreased from 2.8 eV to 2.3 eV and 2.21 eV using 0.25 M of CuSO4 × 5H2O and 0.5 M of CuCl2 × 2H2O, respectively. The effect of copper precursors and concentration of Cu2+ ions on the particle size, chemical composition of NCs and properties has been discussed in detail. Different structural phases of nickel sulfide and copper sulfide were obtained using NiS/FNBR nanocomposites as a precursor for ion exchange reaction by Cu2+ ions. Properties of CuxS-NiySz/FNBR and CuS-NiySz/FNBR nanocomposites obtained after modification have been studied and compared with initial nanocomposite of NiS/FNBR. The average particle size increased from 8.5 nm to 13.5 nm and 15 nm after ion exchange modification. By EPR spectrum the superhyperfine splitting is seen in the spectrum of CuS-NiySz/FNBR, ACu = 107.3 G. In perpendicular section the bandwidth of the spectrum (ΔH) is equal to 930 G. Recording to SEM images very clearly imaged spherical nanoparticles have been observed.

A series of polyfunctionalized 2-amino-1-methyl-6-(methylthio)-5-nitro-4-aryl-1,4-dihydropyridine-3-carbonitriles have been prepared using a multicomponent condensation reaction between aromatic al...

Two known organotin(IV) complexes, [Sn(C6H5)3HL1] (1) and [Sn(C2H5)2(1κO,2κO-H3L2) (1κO2-H3L2) (μ3-O)]2 (2), were prepared upon interaction of Ph3SnCl and Et2SnO with 2-(2-(2,4-dioxopentan-3-ylidene)hydrazinyl)benzoic acid (H2L1) and 2-(2-(2,4,6-trioxotetrahydropyrimidin-5(2H)-ylidene) hydrazinyl)benzoic acid (H4L2), respectively, in toluene solution. Both complexes are applied as catalysts in cyanosilylation of aldehydes. Complex 2 shows a high catalytic activity in the cyanosilylation reaction of a variety of aliphatic and aromatic aldehydes with trimethylsilyl cyanide yielding to the corresponding cyanohydrin trimethylsilyl ethers (yields up to 99%) in methanol and at room temperature.

The new trinuclear [Co II (H 2 O) 2 (Me 2 NCHO) 2 {Co III (1κ NOO′ :2κ O″ -μ-HL)} 2 (1κ NOO′ )]·2H 2 O ( 1 ) and polymeric [Co II (1κ NOO′ :2κ O″ -μ-HL)(MeOH) 2 ] n ( 2 ) complexes were isolated by the reaction of ( Z )-2-(2-(1,3-dioxo-1-(phenylamino)butan-2-ylidene)hydrazinyl)benzoic acid (H 3 L) with CoCl 2 ·6H 2 O and Co(ClO 4 ) 2 ·6H 2 O, respectively, in a mixture of DMF/MeOH (1/10, v/v), in the presence of Et 3 N at room temperature, and characterized by IR and ESI-MS spectroscopies, elemental and X-ray crystal structural analyses. In both structures the cobalt centres display distorted octahedral geometries. The structural units in 1 and 2 are connected via intermolecular hydrogen bonds involving the coordinated HL 2− and the bound and non-bound water molecules (in 1 ) or the methanol ligands (in 2 ) which provides supramolecular networks. 1 and 2 are catalyst precursors for the cyanosilylation reaction of a variety of both aromatic and aliphatic aldehydes with trimethylsilyl cyanide leading to the corresponding cyanohydrin trimethylsilyl ethers in high yields (up to 89%) in methanol and at room temperature.

We reported of synthesis and investigation of the new biologically active derivatives of dihydropyrimidines 2 and 3. The investigation of structures of compounds by various experiments of NMR spectroscopy revealed the splitting of the signals to doublets and multiplets that confirms the presence of diastereomers in solution of compound 2 and the presence of diastereomers and tautomers in solution of compound 3. The individual diastereomer of compound 3 has been isolated. Biological activity of the synthesized compounds was studied on various species of genus Aspergillus fungi.

This work covers the effects of annealing temperature on crystalline size, surface morphology, optical, structural and paramagnetic properties of NiS and Ni3S4 nanostructures grown through SILAR technique into FNBR matrix. Annealing at low temperature was performed in air and vacuum for 8 h. X-ray diffraction results confirm structural phase transitions (like NiS→Ni7S6 and Ni3S4→Ni9S8) and oxidation processes (by the formation of NiO-SO4-H2O) after thermal annealing of nanocomposites (NCs) in a vacuum and in air, respectively. By EDX spectrum the average Ni:S atomic ratio is approximately 1:1 for as-prepared NiS, 1:0.89 for NiS annealed in a vacuum and 1:0.91 for NiS annealed in air.

The new copper(II) complexes [Cu(HL1)(H2O)(CH3OH)] (1, H3L1 = (Z)-2-(2-(1,3-dioxo-1-(phenylamino)butan-2-ylidene)hydrazinyl)benzoic acid) and [Cu(HL2)(H2O)(CH3OH)] (2, NaH2L2 = sodium (Z)-2-(2-(1,3-dioxo-1-(phenylamino)butan-2-ylidene)hydrazinyl)benzenesulfonate) were synthesized and characterized by IR and ESI-MS spectroscopies, elemental and X-ray crystal structural analyses. The coordination environment of the central copper(II) has a square pyramidal geometry, three sites being occupied by (HL1,2)2−, which chelates in the O,N,O fashion, while the two other sites are filled with the water and methanol ligands. Multiple intra- and intermolecular non-covalent interactions between the (HL1,2)2−, water and methanol ligands lead to supramolecular network. Both compounds 1 and 2 act as homogenous catalysts for the cyanosilylation reaction of a variety of both aromatic and aliphatic aldehydes with trimethylsilyl cyanide affording the corresponding cyanohydrin trimethylsilyl ethers in high yields (up to 90%) and at room temperature.

The new 1D copper(II) coordination polymers (CPs) [Cu(μ-L1)(H2O)]n (1, H2L1 = 2-(2-(4,4-dimethyl-2,6-dioxocyclohexylidene)hydrazinyl)benzoic acid) and [Cu(μ-H2L2)(H2O)]n (2, H4L2 = (Z)-2-(2-(1,3-dioxo-1-(phenylamino)butan-2-ylidene)hydrazinyl)terephthalic acid) and the known zwitterionic 1D CP [Cu2(H2O)2(μ-H2L3)(μ-L3)]n (3, H3L3 = 2-(2-(4,4-dimethyl-2,6-dioxocyclo-hexylidene)hydrazinyl)terephthalic acid) were synthesized and tested as homogeneous catalysts for cyanosilylation of a variety of aldehydes to the corresponding cyanohydrin trimethylsilyl ethers. Among these polymeric catalysts, 3, with a zwitterionic charater, is the most effective one, giving 86–99% yield of the ethers upon reaction of aliphatic and aromatic aldehydes with trimethylsilyl cyanide in methanol at room temperature in 4 h. Non-covalent interactions (cation-π and tetrel bondings) involving the aldehyde substrate are proposed to assist the cyanosilylation reaction.

Sodium 2-(2-(1-cyano-2-oxopropylidene)hydrazinyl)benzenesulfonate (NaHL) was synthesized by azocoupling of diazonium salt of 2-aminobenzenesulfonic acid with 3-oxobutanenitrile and characterized by IR, 1H and 13C NMR spectroscopies and ESI-MS analysis. In dimethylsulfoxide-d6 solution NaHL exists as a mixture of Z- and E-hydrazone forms in the amounts of 96 and 4%, respectively. Treatment of this isomeric mixture with copper(II) nitrate hydrate in the presence of ethylenediamine (en) provides unusual (E,Z) → E switching of NaHL to give [Cu(H2O)2(en)2](HL)2 (1). The process is interpreted on the basis of cooperative ionic interactions and resonance assisted hydrogen bonding (RAHB) → charge assisted hydrogen bonding (CAHB) transition.

Here is reported the synthesis of o-phenylenediamine functionalized graphite (OPDFG) using the phosphorus trichloride surface modified graphite (PCl3-SMG) and the o-phenylenediamine (OPD). PCl3-SMG was obtained via chlorophosphorylation of graphite for the study. PCl3-SMG and OPDFG were analyzed using ultraviolet-visible (UV-Vis) spectroscopy, Fourier transform infrared (FTIR) spectroscopy, powder X-ray diffraction (XRD) and Scanning Electron Microscope (SEM). UV-Vis analysis shows that OPDFG have higher absorbance than graphite and PCl3-SMG. According to FTIR analysis, PCl3-SMG has –PCl2 functional groups, which shows that PCl3 reacts with sp2 C-H groups on graphite's edge planes during the formation of PCl3-SMG. Synthesis of OPDFG can be explained by a replacement reaction of amine groups of OPD with –PCl2 groups. XRD data show that after modification of graphite with PCl3 and after amine treatment of PCl3-SMG, crystallite sizes of PCl3-SMG and OPDFG decrease. SEM analysis shows that both PCl3-S...

New 2-amino-4-aryl-3-cyanopyridines were obtained by the three-component condensation of arylidenemalononitriles, malononitrile and (di)amine system or acetoacetanilide. Antibacterial activity of all synthesized compounds against the Gram-negative bacteria E. coli and the Gram-positive B. subtilis was tested, the only representative showed a substantial antimicrobial effect.

In the crystal of the title salt, the cations and anions are linked via N—H⋯Br hydrogen bonds to form a three-dimensional network., In the cation of the title salt, C9H12N3S+·Br−, the thia­zolidine ring adopts an envelope conformation with the C atom adjacent to the phenyl ring as the flap. In the crystal, N—H⋯Br hydrogen bonds link the components into a three-dimensional network. Weak π–π stacking inter­actions between the phenyl rings of adjacent cations also contribute to the mol­ecular packing. A Hirshfeld surface analysis was conducted to qu­antify the contributions of the different inter­molecular inter­actions and contacts.

In the cation of the title salt, the central thiazolidine ring adopts an envelope conformation. In the crystal N-H⋯Br hydrogen bonds link the components into a bi-dimensional network with the cations and anions stacked parallel to plane (101). The molecular structure shows several positional disorders over -CF3 and thiazolidine fragments and these were modeled. The weak intermolecular interactions in the crystal structure are mainly constituted by H⋯F, H⋯π and H⋯Br. Hirshfeld surface analysis were used to verify the contributions of the different intermolecular interactions.

Ni/NiO nanochains were successfully synthesized by a facile and environmentally friendly chemical reduction method under different magnetic fields, followed by thermal oxidation at high temperatures. For the synthesis of Ni nanoparticles, hydrazine hydrate and sodium borohydride were used as reducing agents. In order to determine the size, structure, optical properties and morphology, the obtained products were characterized by X-ray diffraction (XRD), ultraviolet–visible Spectroscopy (UV–Vis), transmission electron microscopy (TEM) and scanning electron microscopy (SEM). Additionally, the effect of reaction time, different magnetic field intensity and oxidation temperature on the size and morphology of synthesized nanoparticles was investigated in detail. The average size of as-prepared Ni nanoparticles in nanochain decreases with increasing magnetic force. After oxidation of samples at 600 °C, the size of NiO formed on the surface of Ni nanochains increases with increasing magnetic force. This is related to the faster oxidation of small particles due to their high surface energy. According to TEM measurements, the average diameter of Ni/NiO nanochains (synthesized at 25 mT after oxidized at 600 °C) is in the range of 97–133 nm and spherical particles are assembled in the form of a chain-like, which confirms SEM results.

The influence of corona discharge on the structure and photoluminescence properties of nanocomposites based on polypropylene and zirconium dioxide nanoparticles has been studied. It is shown that a...

Three new water-soluble copper(II) complexes [Cu(HL)(H2O){(CH3)2NCHO}] (1), [Cu(H2L)2(im)4]·CH3OH (2) and [Cu(HL)(CH3OH)]2(μ2-py) (3) were synthesized from copper(II) nitrate and sodium (Z)-2-(2-(1,3-dioxo-1-(phenylamino)butan-2-ylidene)hydrazinyl)benzene-sulfonate (NaH2L), in the absence (for 1) and presence of imidazole (im) (for 2) or pyrazine (py) (for 3), and fully characterized. The complexes 1–3 have been tested as stereoselective C H activating catalysts for the model nitroaldol (Henry) condensation of nitroethane with various aldehydes in water. 1 was the most active catalyst affording 64−87% yields with syn/anti diasteroselectivities up to 77:23.

According to an X-ray diffraction study, pyridine-2-selenenyl chloride (1) characterized by unusually high stability both in solutions and in the solid state adopts a dimeric structure formed by two secondary intermolecular Se···N interactions. However, it slowly transforms into zwitterionic T-shaped pyridinium-2-selenenyl dichloride (2) in a dichloromethane solution. Conformational features, electronic structures, and reactivities of 1 and 2 are discussed on the basis of experimental and theoretical (quantum chemical calculations) data.

The reaction of 2,4-diacetyl-5-hydroxy-5-methyl-3-phenylcyclohexanone-1 with phenylhydrazine is conducted, and the crystal structures of its products, 1-(6-hydroxy-3,6-dimethyl)-2,4-diphenyl-4,5,6,7-tetrahydro-2H-indazol-5-yl)ethane-1-one and 1-(2-hydroxy-2-methyl-6-phenyl-4-(2-phenylhydrazono)-5-(1-(2-henylhydrazono)ethyl)cyclohexyl)ethane-1-one, are determined by single crystal XRD.

Nickel sulfide nanostructures have been successfully prepared with two different sulfur sources like thiourea (S C(NH 2 ) 2 ) and sodium sulfide by the successive ionic layer adsorption and reaction (SILAR) method. The functionalized nitrile-butadiene rubber (F-NBR) was used as stabilizing agent for formation of nickel sulfide semiconductor nanoparticles. The nanoparticle sizes correspond to 8.5 nm and 7 nm using thiourea and sodium sulfide respectively. The as-synthesized NiS and Ni 3 S 4 nanostructures were characterized by XRD, SEM, EDX, UV–vis and FTIR spectroscopy methods. A systematic investigation of the final end products has been done to elucidate the formation mechanism at different experimental parameters. Using thiourea the optical band gap of NiS for 4, 6 and 8 cycles were determined to be 3.12, 2.93 and 2.81 eV, respectively. The optical band gap of Ni 3 S 4 for 6 and 8 cycles were determined to be 2.8 and 2.15 eV, respectively.