Vol 86, No 5 (2016)

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.

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.

The Stevens rearrangement of ammonium salts with two propargyl group at the ammonium nitrogen results in the formation of amines containing acetylene-acetylene and acetylene-allene fragments.

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.

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.

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.

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.

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.

Cobalt and copper tetra-[4-(9,10-dioxo-9,10-dihydroanthraceny-2-yl)]- and tetra-{4-[(9,10-dioxo-9,10-dihydroanthracen-2-yl)oxy]}phthalocyanines have been prepared; their spectral properties have been studied.

Structural parameters and IR spectra of the (¹A₁//C_4v)-PcLuCl, (²B₂//C_4v)-PcYbCl, and (⁸A₂//C_4v)-PcGdCl molecules, (²A₂//C_4v)-Pc⁺LuCl, (3B₁//C_4v)-Pc⁺YbCl, and (⁹A₁//C_4v)-Pc⁺GdCl cations, (¹A_g//D_2h)-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//C_4v)-Pc¹⁷⁷LuCl → (¹A₁//C_4v)-(Pc^177mHfCl)⁺ occurs with no significant change of the charge on the metal atom.

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.

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.

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.

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.

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.

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⁺)[Fe^III(TAR^2–)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.

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.