Vol 87, No 7 (2017)

Electronic structure of (SiO₂)₃ clusters was calculated by the density functional method. Charge states were determined using various functionals, bond lengths and total energies of clusters were estimated.

Thermal reduction of graphite oxide and its derivatives under argon atmosphere has been studied by means of thermogravimetric analysis. Carbon materials prepared via thermal reduction of graphite oxide derivatives in argon at 900°С during 3 h have been used for deposition of platinum from H₂PtCl₆ solutions. Pt particles supported on the support catalyze liquid-phase hydrogenation of nitrobenzene and dec-1-ene under atmospheric pressure of H₂. Thermal reduction of the supports based on graphite oxide results in the formation of the structural defects significantly enhancing the catalytic activity.

Radiolysis of aqueous solutions of diisopropyl and methyl tert-butyl ethers under γ-irradiation has been studied. The effect of pH on the products yield has been investigated. It has been shown that the rate constants of ether radicals hydrolysis are ~10⁹ times higher than these of ether molecules in acidic as well as basic medium.

Reaction of methyl 2,4-dioxobutanoates with tetracyanoethylene yielded methyl 3-acyl-4-cyano-5-(dicyanomethylene)-2-hydroxy-2,5-dihydro-1H-pyrrole-2-carboxylates. X-Ray diffraction data showed that 3-acyl-4-cyano-5-(dicyanomethylene)-2-hydroxy-2,5-dihydro-1H-pyrrole-2-carboxylic acid methyl esters can form supramolecular structures with one-dimensional channels which make possible inclusion of large organic and bioorganic molecules.

Reactions of (E)-[(2-aroyl)ethenyl]triphenylphosphonium bromides with hydroxylamine hydrochloride resulted in the formation of oximes undergoing α-phenyl migration when reacted with aqueous alkali. Reaction of these salts with hydrazine hydrochloride and o-phenylenediamine yielded [(2-aroyl)ethyl]triphenyl-phosphonium salts and phosphorus-substituted quinoxalines, respectively.

Reactions of furyl(diethoxyphosphoryl)acetic aldehyde containing ester or cyano group in the furan ring with ethoxycarbonylmethylenetriphenylphosphorane has been shown to afford alkyl E-4-(furyl)-4-(diethoxyphosphoryl)but-3(2)-enoates. When treated with potassium tert-butoxide the mixture of alkyl E-4-(3-ethoxycarbonylfur-2-yl)-4-(diethoxyphosphoryl)but-2-enoate and -but-3-enoate gives a potassium salt of CHacid. Its acidifying results in a mixture of starting compounds with a larger amount of -but-3-enoate. Under analogous conditions the mixture of alkyl E-4-(2-ethoxycarbonylfur-3-yl)-4-(diethoxyphosphoryl)but-2-enoate and -but-3-enoate undergoes cyclization to a phosphorylated derivative of alkyl 7-hydroxybenzofuran-6-carboxylate. The cyclization of the mixture of alkyl E-4-(4-ethoxycarbonylfur-3-yl)-4-(diethoxyphosphoryl)but-2-enoate and -but-3-enoate gives analogous derivative of isobenzofuran.

Reactions of (4-methoxyphenyl)amine and its trimethylsilyl derivative with organosilicon isocyanates and phenylisocyanate have been studied. (4-Methoxyphenyl)formamide was first synthesized by the reaction of (4-methoxyphenyl)amine with ethyl formate. The structure of trimethylsilyl(4-methoxyphenyl)-carbamate and N-(4-methoxyphenyl)formamide was determined by X-ray diffraction (XRD) analysis.

The fixation and activation of molecular oxygen on copper(II) complexes with 5-hydroxy and 5-aminoorotic acids, leading to oxidation of the ligand.

The complex formation of zinc(II) acetate with monoiodo- and dibromo-substituted dipyrromethenes in DMF at 298.15 K were studied by means of spectrophotometric titration. It was found that the process involves consecutive formation of heteroligand [ZnLOAc] and homoligand [ZnL₂] complexes. The thermodynamic stability of halogenated zinc(II) dipyrrolylmethenates [ZnL₂] was studied.

Novel water- and organic-soluble derivatives of octakis-4,5-(sulfanylphenyl)phthalocyanine and its magnesium and aluminum complexes were synthesized starting from 4,5-bis(phenylsulfanyl)phthalonitrile obtained by nucleophilic substitution of the bromine and nitro group in 4-bromo-5-nitrophthalonitrile. Spectral and luminescence characteristics of the newly synthesized compounds were studied.

Bromination of (5,10,15,20-tetraphenylporphyrinato)palladium(II) and [5,10,15,20-tetrakis(4-methoxyphenyl)porphyrinato]palladium(II) with N-bromosuccinimide in chloroform–dimethylformamide and chloroform afforded mono-, tetra-, and octabromo derivatives substituted at the pyrrole rings. The products were identified by electronic absorption, ¹H NMR, and mass spectra and elemental analyses.

Synthesized visnagin-9-sulfonyl esters underwent cleavage of their pyran ring upon treatment by hydroxylamine hydrochloride, hydrazine hydrate and primary amines. Reaction of visnagin-9-sulfonyl chloride 1 with alcohols or phenol gave the corresponding sulfonate derivatives 2, that were treated with hydroxylamine hydrochloride, anilines or hydrazine derivatives to give the corresponding compounds 3–5, respectively. The obtained products demonstrated potent anti-HIV activity.

Condensation reaction between benzildihydrazone and pyridine 2,3-dicarboxylic acid, pyridine 3,4-dicarboxylic acid or pyridine 2,4-dicarboxylic acid in methanol led to novel Schiff base macrocyclic ligands L₁, L₂, and L₃ respectively. Metal complexes of the type [MLCl2], [M = Co(II), Ni(II)], were synthesized by the reaction of a free macrocyclic ligand (L) with the corresponding metal salts in a 1 : 1 molar ratio. The complexes were characterized on the basis of analytical data, molar conductivity and magnetic susceptibility measurements, IR, ¹H, and ¹³C NMR, and electronic spectral data. Those demonstrated that all the complexes had octahedral arrangement around the metal ions. The ligand and its complexes were screened for their antibacterial, antifungal and DNA cleavage activities. The studies demonstrate that the complexes possessed antimicrobial and DNA cleavage activities.

Some novel (4Z)-2-[(E)-2-arylidenehydrazinyl]-4-{[1-(3-chlorophenyl)-3-(4-methoxyphenyl)-1H-pyrazol-4-yl]methylene}-1-phenyl-1H-imidazol-5(4H)-ones have been synthesized in a one-pot threecomponent cyclocondensation of pyrazole-4-carbaldehyde derivative with glycine and different isothiocyanate derivatives. The structures of the newly synthesized compounds were characterized by analytical and spectral data.

Reaction of aromatic aldehydes with aniline and tropylium tetrafluoroborate yielded N-arylmethylene-4-(7-cyclohepta-1,3,5-trienyl)anilines, while reaction of aromatic aldehydes with aniline, tropylium tetrafluoroborate, and sodium tetrahydroborate afforded N-arylmethyl-4-(7-cyclohepta-1,3,5-trienyl)anilines. Two most promising compounds, N-2-hydroxyphenylmethylene-4′-(7-cyclohepta-1,3,5-trienyl)aniline and N-2-hydroxyphenylmethyl-4′-(7-cyclohepta-1,3,5-trienyl)aniline, were tested for acute toxicity (LD₅₀) and their low toxicity was revealed.

Stereoselective synthesis of methyl-(2E,4Z)-deca-2,4-dienoate, a component of sex pheromones of Pityogenes chalcographus and Acanthoscelides obtectus, was performed on the basis of Fe-catalyzed cross-coupling of methyl-(2E,4Z)-5-chloropenta-2,4-dienoate with n-pentylmagnesium bromide.

By the reaction of nucleophilic substitution of chlorine in 1-phenyl-1-chloro-1-silacyclohexane new 1-phenyl-1-X-1-silacyclohexanes (Х = МеО, ОН, Ме₂N) have been synthesized and their stability with respect to the formation of (1,1′-phenyl-1,1′-silacyclohex-1-yl)disiloxane have been investigated.