Том 86, № 5 (2016)
- Год: 2016
- Статей: 42
- URL: https://journals.rcsi.science/1070-3632/issue/view/13375
Article
Thermal oxidation of GaAs under action of V2O5–MnO2 oxide chemostimulating formulations with particles size of 50–150 μm
Аннотация
Thermal oxidation of GaAs under action of V2O5–MnO2 formulations of the different composition with particles size of 50–150 μm has been studied. The revealed nonlinear effect of the combined action of the chemostimulators results from their interference accelerating their transformations, changing their evaporation, and affecting their incorporation into the oxide film growing at the GaAs surface.
Influence of ZrO5 treatment temperature on the interaction with titanium tetrachloride
Аннотация
The data on phase and chemical transformations of nanosized zirconium dioxide upon annealing at 25–1300°С are presented. The in situ interaction of titanium tetrachloride with nanosized zirconia annealed at 200–800°С has been studied. The revealed regularities of the change of titanium content and the Cl/Ti ratio in the chemisorbed groups have confirmed that TiCl4 predominantly reacts with zirconia treated at up to 400°С via the hydroxyl groups to yield the TiCl4–n fragments. In the case of zirconia treated at higher temperature, the interaction with TiCl4 involves the coordination-unsaturated Zr+ and Zr–O– centers as well.
Enthalpy of mixing in the propylene oxide–dimethylformamide and propylene oxide–ethylene glycol systems
Аннотация
Heat of mixing of propylene oxide with N,N-dimethylformamide and ethylene glycol has been determined by means of microcalorimetry. Theoretically suggested choice of the aprotic solvent as a selective separating agent for the propylene oxide–methanol binary mixture has been experimentally justified.
Interaction of nitrogen-containing propargyl compounds with CH-acids in the presence of mercury(II) acetate
Аннотация
Regiochemistry of the reaction of nitrogen-containing propargyl compounds with CH-acids in the presence of mercury(II) acetate has been studied. The possibility of alkylation at the substituted carbon atom of the triple bond of the nitrogen-containing propargyl compounds by sodium salts of acetylacetone and acetoacetic ester with the formation of prototropic isomers has been shown.
Synthesis of triarylimidazole hybrid compound with switchable luminescence
Аннотация
A novel hybrid compound composed of substituted imidazole and salicylideneaniline luminophors has been synthesized and shown to exhibit multiple luminescence in ethanol, which can be switched by varying the excitation wavelength.
Catalytic alkylation of substituted indoles with (phenothiazin-10-yl)propene-1-ones
Аннотация
Alkylation of substituted indoles (carbazoles, tetrahydrocarbazoles, and gamma-carbolines) with (phenothiazinyl)propenones catalyzed by cesium fluoride has led to the formation of 1-(phenothiazin-10-yl)-3-(carbazol-9-yl)propane-1-ones, (1-phenothiazin-10-yl)-3-(tetrahydrocarbazol-9-yl)propane-1-ones, and 3-(tetrahydropyrido[4,3-b]indol-5-yl)-1-(phenothiazin-10-yl)propane-1-ones, respectively.
Synthesis and biological activity of new hybrids compounds derived from benzofuroxanes and polyene antibiotics
Аннотация
Hybrid compounds based on 4,6-dichloro-5-nitrobenzofuroxan, 7-chloro-4,6-dinitrobenzofuroxan, 5,7-dichloro-4,6-dinitrobenzofuroxan, and polyene antibiotics (amphotericin B and nystatin) have been prepared for the first time. They have exhibited biological activity comparable to that of starting antibiotics. Activity of the compound derived from 5,7-dichloro-4,6-dinitrobenzofuroxan and nystatin towards Trichophyton mentagrophytes is 4 times higher than that of nystatin.
Reactions of but-2-yne-1,4-diylbis(triphenylphosphonium) dihalides with SH- and NH-nucleophiles
Аннотация
But-2-yne-1,4-diylbis(triphenylphosphonium) diiodide reacts with 2-sulfanylethan-1-ol in the presence of triethylamine to form a 1 : 1 adduct. Under similar conditions, ethane-, butane- and 2-methylbutane- 1-thiols form [4-(alkylsulfanyl)buta-1,3-dien-1-yl]triphenylphosphonium iodides, probably via β-cleavage of the original salt involving vinylethynyl intermediate. Features of the reaction of but-2-ynebisphosphonium salt with 3,5-dimethylpyrazole, hydrazine and its derivatives have been studied.
Furoyl phosphonates
Аннотация
A series of furoyl phosphonates bearing methyl, methoxymethyl, and diethoxyphosphorylmethyl groups in the furan ring have been synthesized via the Arbuzov reaction from the corresponding acid chlorides. NMR spectral parameters of the prepared compounds were studied. The values of coupling constants between the phosphorus nuclei and the carbon nuclei of the furan ring have been examined with relation to the location of the acylphosphoryl group in the furan ring, the nature of second substituent, and location of the latter with respect to the phosphorus-containing substituent in the furan ring. The substitution in position 4 of the furan ring of 3-furoyl phosphonates has been shown to strongly decrease the value of the coupling constant between the phosphorus nucleus and the C2 atom of the heterocycle. The interaction between the phosphorus nuclei has not been detected in the spectra of the compounds containing both diethoxyphosphorylmethyl and acylphosphonate fragments.
Absorption and luminescence spectra of 5-aryl-3-methyl-1,2,4-oxadiazoles and their chelate complexes with Zinc(II) and copper(II)
Аннотация
5-(2-Hydroxyphenyl)-3-methyl-1,2,4-oxadiazole and its O-methyl and O-acyl derivatives, as well as zinc(II) and copper(II) chelates, were synthesized. All these compounds showed luminescence with the emission maxima ranging from λ = 332 to 490 nm, but only 5-(2-methoxyphenyl)- and 5-(2-acetoxyphenyl)-3-methyl-1,2,4-oxadiazoles and zinc(II) complex of 5-(2-hydroxyphenyl)-3-methyl-1,2,4-oxadiazole were characterized by high luminescence quantum yield (φ = 0.308–0.452, 0.089–0.153, and 0.115–0.334, respectively). Stable conformers of 5-(2-hydroxyphenyl)-3-methyl-1,2,4-oxadiazole with different structures of the coordination entity were identified by DFT quantum chemical calculations.
Salicylic aldehyde and 2-N-tosylaminobenzaldehyde tetrazolyl hydrazones and their complexes
Аннотация
Tetrazolyl hydrazones of salicylic aldehyde and 2-N-tosylaminobenzaldehyde as well as zinc(II) and copper(II) complexes on their base have been prepared. Quantum-chemical simulation of tautomerism of the hydrazones in vacuum and in the solutions has been performed. IR and NMR spectroscopy and magnetochemistry studies have revealed that the complexes are mononuclear; however, weak intermolecular exchange interaction of the antiferromagnetic type has been detected in the copper(II) complexes.
Complex formation of magnesium and calcium ions with trimethylenediamine-N,N,N’,N’-tetraacetic acid
Аннотация
Stability constants and heat effects of the formation reactions of magnesium and calcium trimethylenediaminetetraacetates at 298.15 K and ionic strength of 0.1, 0.5, and 1.0 (mol/L KNO3) have been determined by means of potentiometry and calorimetry. Standard thermodynamic parameters (log K0, ΔrG0, ΔrH0, and ΔrS0) of the studied equilibriums have been determined.
Synthesis and structure of tris(3-methylphenyl)bismuth bis(3,4-dimethylbenzenesulfonate)
Аннотация
Tris(3-methylphenyl)bismuth bis(3,4-dimethylbenzenesulfonate) has been synthesized via the reaction of tris(3-methylphenyl)bismuth, 3,4-dimethylbenzenesulfonic acid, and hydrogen peroxide (1: 2: 1) in diethyl ether. Bismuth atoms in the product molecule have the trigonal bipyramidal coordination with arenesulfonate substituting groups in the axial positions.
Specific features of oxidation of ferrocenylmethanol with hydrogen peroxide in acidic media
Аннотация
Two types of transformations (the metal complex protonation and oxidation) have been revealed in the ferrocenylmethanol–Н2О2–НХ system (HX = HClO4, CF3COOH) by means of electronic spectroscopy. The efficiency of protonation has been determined from the intensity of the FcCH2+ carbocation absorption band (λmax = 600 nm); it depends on the acid strength and relative concentration as well as the solvent nature. Kinetics of ferrocenylmethanol oxidation in dioxane has been studied in the presence of trifluoroacetic acid. Two alternative reaction mechanisms have been proposed, differing in the coordination type of the reagents.
Synthesis and properties of bromine-substituted Co(II) tetraphenylporphyrinates
Аннотация
The interaction of bromine-substituted tetraphenylporphyrins with cobalt(II) acetate in a chloroform–methanol mixture yielding the corresponding cobalt(II) porphyrinates has been studied by means of spectrophotometry. Treatment of Co(II) porphyrinates with bromine in the same medium has afforded the Co(III) porphyrinates.
Quantum-chemical study of lutetium, ytterbium, and gadolinium phthalocyaninates PcLnCl
Аннотация
Structural parameters and IR spectra of the (1A1//C4v)-PcLuCl, (2B2//C4v)-PcYbCl, and (8A2//C4v)-PcGdCl molecules, (2A2//C4v)-Pc+LuCl, (3B1//C4v)-Pc+YbCl, and (9A1//C4v)-Pc+GdCl cations, (1Ag//D2h)-PcLuCl2LuPc dimer, and PcLuCl···PcLuCl coaxial molecular pair have been simulated using the DFT (U) PBE0/SDD method. The PcLnCl (Ln = Lu, Yb, Gd) molecules have exhibited the equilibrium Ln–N bond length of 222, 223, and 230 pm, the Ln–Cl bond length of 245, 246, and 253 pm, the dipole moment of 4.73, 4.57, and 4.84 D directed from Cl to Ln, and ionization potential of 6.6 eV. β-Decay (1A1//C4v)-Pc177LuCl → (1A1//C4v)-(Pc177mHfCl)+ occurs with no significant change of the charge on the metal atom.
DFT analysis of molecular structure of 14-membered tetraaza-, dioxotetraaza-, and hexaazamacroheterocyclic ligands and their metal complexes
Аннотация
The structure of 14-membered macrocyclic chelants 1,4,8,11-tetraazacyclotetradecane-2,3,9,10-tetrathione, 1,3,6,8,10,13-hexaazacyclotetradecane-4,5,11,12-tetrathione, and 1,8-dioxa-3,6,10,13-tetraaza-cyclotetradecane- 4,5,11,12-tetrathione as well as their complexes with M(II) metals (M = Cr, Mn, Fe, Co, Ni, Cu, and Zn) has been simulated using OPBE/TZVP density functional method.
The effect of chemical composition of the fullerene on the conformational preference of the encapsulated hexafluoroethane molecule
Аннотация
Study of the structure and conformational behavior of hexafluoroethane encapsulated in the С60 and С80 fullerenes as well as their boron- and nitrogen-containing analogs by means of the PBE/3ζ hybrid DFT method has revealed that the encapsulated molecule exhibits the shortened С–С bond, bears certain electrical charge, and shows significant increase of the potential barrier of rotation around the C–C bond. In the cases of the С60 and С80 analogs doped with boron and nitrogen atoms, the marked effects are weaker.
Synthesis and characterization of new acyclic nucleosides analogues derived from 2-phenyl quinoline candidates
Аннотация
Reaction of 4-substituted quinoline hydrazide with some aldohexoses and aldopentoses gave a series of new N-β-glycosides. The following cyclization of N-β-glycosides with acetic anhydride led to O-acetyl-[5-(2-phenylquinolin-4-yl)-1,3,4-oxadiazol-2-yl]-D-glycosides. Structure of the newly synthesized products was elucidated by chemical and spectroscopic methods.
Solvent-free microwave assisted synthesis of morpholine–piperidine–pyrrolidine annulated quinoline-naphthyl based chalcones and their antimicrobial activity
Аннотация
A new series of 2-morpholine–piperidine–pyrrolidine substituted quinoline based chalcones have been synthesized by conventional and microwave irradiation methods. All synthesized compounds were characterised by IR, 1H and 13C NMR, mass spectrometry, and elemental analysis. The products were evaluated in vitro for antibacterial activity against two bacterial strains (Staphylococcus aureus, Escherichia coli) and antifungal activity against two fungal strains (Aspergillus flavus, Candida metapsilosis). 2-Piperidine substituted quinoline chalcones demonstrated high antimicrobial activity.
Synthesis of novel substituted pyrano annulated flavones
Аннотация
A simple and efficient one pot method has been developed for the synthesis of some new functionalized pyrano fused flavone derivatives, alkyl 4,8-dioxo-2-phenyl-4,8-dihydropyrano[2,3-f]chromene-10-carboxylates and dialkyl 4-oxo-2-phenyl-4,8-dihydropyrano[2,3-f]chromene-8,9-dicarboxylates, from 7-hydroxy flavones and 7-hydroxy 8-formyl flavones using dialkylacetalynedicarboxylates in the presence of triphenyl phosphine. The structures of all synthesized compounds were elucidated by FT-IR, 1H and 13C NMR and Mass spectral analysis.
Neat synthesis of octahydroxanthene-1,8-diones, catalyzed by silicotungstic acid as an efficient reusable inorganic catalyst
Аннотация
In this article, the first use of silicotungstic acid (H4SiW12O40) as a catalyst for the synthesis of octahydroxanthene-1,8-diones by the reaction of 5,5-dimethylcyclohexane-1,3-dione (dimedone) with various aldehydes under thermal solvent-free conditions is described. The obtained results showed that the catalyst has a high catalytic activity, and the desired products were obtained in high yields. Moreover, the catalyst was found to be reusable, and a considerable catalytic activity still could be achieved after the fifth run. Easy work-up and avoidance of using harmful organic solvents are the other advantages of this simple procedure.
Synthesis, characterization, and cytotoxic in vitro studies of the antibiotic drug metronidazole complexed with Au(III), Fe(III), Pd(III), and Zn(II): Toward potent gold-drug nanoparticles in cancer chemotherapy
Аннотация
Prolifiration of cancer incidents over recent decades has motivated researchers to explore new metal complexes with potential anticancer properties as alternative chemotherapeutic agents in clinical treatments. Au3+, Fe3+, Pd3+, and Zn2+ complexes of the drug metronidazole (MZ) were synthesized and characterized in the current study by elemental analysis, magnetic moment, molar conductance, UV–Vis, IR, Raman, and 1H NMR spectroscopy. Morphology and nanometry of the complexes have been studied by XRD, SEM, and TEM techniques. In vitro cytotoxicity of the Au(III) complex against two human tumor cell lines was assessed by the MTT method. The Au(III) complex formed well-organized nanoparticles with the main diameter in the range of 6–34 nm. It exhibited the significant cytotoxic effect against human hepatocellular carcinoma cells with potency caю 7.5 times greater than that of free MZ.
Efficient synthesis of bis-indolyloxindoles from (phenylimino)indolin-2-ones and 1H-indole catalyzed by p-toluenesulfonic acid
Аннотация
p-Toluenesulfonic acid (p-TSA) efficiently catalyzed the reaction of (phenylimino)indolin-2-ones with 1H-indole in dichloromethane at room temperature to afford 3,3-di(indolyl)indolin-2-ones in 2-3 min with high yields.
Synthesis and spectroscopic studies of the new Ag(I) organoselenium complex
Аннотация
The new complex of Ag(I) with an organoselenium compound was synthesized. The 2 : 1 (silver : ligand) stoichiometry of the complex and chelating mode of the hetero-selenium ligand have been considered on the basis of elemental analyses, IR, Raman, 1H and 13C NMR, and thermogravimetric data. The IR spectrum of the complex supported two sites of coordination (selenium and nitrogen atoms of quinoline moiety). The bidentate ligand was bound to selenium via oxygen atoms of the carboxylate group. The complex demonstrated the non-electrolyte nature. Nano-scale range of Ag(I) complex has been estimated according to X-ray powder diffraction, scanning electron microscope and transmission electron microscopy.
Synthesis, biological evaluation, and molecular docking studies of novel 1,2,3-triazole derivatives as potent anti-inflammatory agents
Аннотация
In the present study, a novel series of 1,2,3-triazole derivatives have been synthesized using click chemistry approach. The structures were confirmed by spectroscopic methods. The products were screened for their in vivo anti-inflammatory activity. The tested compounds 6a, 6f, 6g, 6i, 6j, 6n, and 6p, demonstrated potent anti-inflammatory activity compared to the reference drug ibuprofen. Molecular docking studies of these 1,2,3-triazole derivatives into the active site of human cyclooxygenase-2 (COX-2) (PDB code 4PH9) demonstrated good affinity for the enzyme and suggested binding properties similar to ibuprofen.
Synthesis of 5-tert-butyl-1,2,3-trimethylbenzene catalyzed by [Et3NH]Cl–AlCl3
Аннотация
Common Lewis acids and Lewis acidic ionic liquid catalysts were applied in the synthesis of 5-tert-butyl-1,2,3-trimethylbenzene from 1,2,3-trimethylbenzene and 2-chloro-2-methylpropane, where [Et3NH]Cl–AlCl3 demonstrated the most promising catalytic potential. The effects of reaction time, temperature, catalyst composition and dosage have been systematically studied in the presence of [Et3NH]Cl–AlCl3. The maximum selectivity of 90.32% was achieved upon heating at 10°C for 5 h with a mass fraction of [Et3NH]Cl–AlCl3 to 1,2,3-trimethylbenzene of 10%. Activity of the ionic liquid catalyst remained high after several cycles.
Specific features of tetranitrotetrazolium blue chloride as an extraction reagent for iron(III)
Аннотация
A liquid-liquid extraction-chromogenic system containing Fe(III), 4-(2-thiazolylazo)resorcinol (TAR), [3,3’-(3,3’-dimetoxy-4,4’-biphenylene)bis[2,5-di(4-nitrophenyl)-2H-tetrazolium] chloride (tetranitro-tetrazolium blue chloride, TNBT), water, and chloroform was studied and compared with similar systems containing such ditetrazolium salts (DTS), as neotetrazolium chloride (NTC), blue tetrazolium chloride, and nitro blue tetrazolium chloride. The results show that the complex formed in the Fe(III)–TAR–TNBT system is of different composition (1 : 3 : 2 vs. 1 : 2 : 1) and has better extraction-spectrophotometric characteristics (fraction extracted is 98.6 % and molar absorptivity, 7.8 × 104 dm3 mol–1 cm–1 at λ = 495 nm). The proposed formula of the complex is (TNBT+)[FeIII(TAR2–)2]·{(TNBT+)(HTAR–)}, where TNBT is in the monocationic form. The geometry optimization for TNBT and NTC–the DTS, which does not contain nitro- and methoxy groups, was performed by the Restricted Hartree–Fock (RHF) method with the 3-21G* basis set. The obtained results (ground-state structures and total atomic charges) for TNBT, TNBT+, TNBT2+, NTC, and NT2+ were compared and discussed.
Straightforward and solvent-free synthesis of 2-amino-4H-chromenes in the presence of a choline-based magnetic ionic liquid as catalyst
Аннотация
Choline tetrachloroferrate with a magnetic response property is applied in multicomponent one-pot synthesis of 2-amino-4H-chromenes as effective catalyst. The catalyst is characterized by the UV–Vis and Raman spectroscopies and by the electrospray ionization mass spectrometry.
Co(II) and Ni(II) complexes with Schiff base ligands: Synthesis, characterization, and biological activity
Аннотация
The ligands, 1-acetylferrocenehydrazinecarboxamide (HL1) and 1-acetylferrocenehydrazinecarbothioamide (HL2), and their Ni(II) and Co(II) complexes were synthesized. The properties of the synthesized compounds were determined by the elemental and spectroscopic analyses. Ni(II) and Co(II) acetates interact with the ligands at the molar ratios 1 : 1 and 1 : 2 to give coloured products. The complexes have octahedral geometry. The ligands are coordinated to Co(II) and Ni(II) centers via the azomethine nitrogen and thiolic sulfur /enolic oxygen atom. The ligands and their Co(II) and Ni(II) complexes were screened for antibacterial and antifungal activities. The Co(II) and Ni(II) complexes show enhanced inhibitory activity as compared to their parent ligands. The DNA cleavage activity of the Co(II) and Ni(II) complexes was determined by gel electrophoresis. It was shown that the complexes have better cleavage activity than the ligands. The antioxidant activity of the complexes was also evaluated and used to examine their scavenging ability on hydrogen peroxide.