Biological Properties of Antimony(III) Fluoride Complexes

Result of a study of how antimony trifluoride and fluoride complexes MSb₂F₇ (M = K, Rb, Cs, Tl, NH₄), MSbF₄ (M = Na, K, Rb, Cs, NH₄), and M₂SbF₅ (M = Na, K, Rb, Cs, Tl, NH₄) affect the growth of associations of marine bacteria and vital activity of marine alga Ulva Fenestrata are presented. The possible ways of using Sb(III) fluoride compounds are discussed.     

Complexes of crown ethers with perfluorocarboxylic acids and their thermal decarboxylation

Crown ethers form strong proton-acceptor complexes with CF₃COOH or C₄F₉COOH that undergo thermal decarboxylation at 200–260 °C which results in 60–80% of CF₃H or C₄F₉H (including up to 20 % of a mixture of C₄F₈). Critical parameters of the process were determined in relation to the temperature and amount of crown ether. The relative activities of different crown ethers in decarboxylation were also established. A scheme is proposed that explains the effect of the structure of crown ethers on this reaction. The data obtained substantiate the view that the topological correspondence concept is insufficient to explain the ability of crown ethers to form complexes with cations.Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 6, pp. 1098–1101, June, 1993.     

IR spectroscopy and single crystal X-ray diffraction study of 1,2-bis(2-aminophenoxy)-ethane, 1,5-bis(2-aminophenoxy)-3-oxapentane,and 1,8-bis(2-aminophenoxy)-3,6-dioxaoctane

Vibrational spectra of 1,2-bis(2-aminophenoxy)-ethane, 1,5-bis(2-aminophenoxy)-3-oxapentane, and 1,8-bis(2-aminophenoxy)-3,6-dioxaoctane–podands, different in the length of oxyethylene fragments, are measured and their single crystal X-ray diffraction analysis is performed. It is demonstrated that the strength of intermolecular hydrogen bonds (IMHB) with the participation of NH groups increases with the elongation of the oxyethylene spacer. According to the XRD data for 1,2-bis(2-aminophenoxy)-ethane, the weakest hydrogen bonds are characteristic. From the IR spectra, important intermolecular hydrogen bonds are typical of 1,8-bis(2-aminophenoxy)-3,6-dioxaoctane having the longest oxyethylene fragment.     

Development of a method for the thiocarbamoylation of polyepichlorohydrin with a high degree of functionalization

Russian Chemical Bulletin - The conditions for the homogeneous functionalization of polyepichlorohydrin (PECH) with thiourea by the “synthesis in gel” method were experimentally...     

Activated carbon and carbon-oxide composite materials derived from powdered cellulose

Activated carbons were prepared by high-temperature steam activation of carbonized samples of powdered cellulose and composite cellulose-inorganic materials based on it. The dependences of the yield of the material and in its physicochemical characteristics on the initial formula of the composite were found. The sorption activity of the carbons toward hydroquinone was determined, and the model reaction of hydrogen peroxide decomposition in their presence was performed.     

IR-Spectroscopic Study of Adsorption of Aminoazoles on Oxide Catalysts of Biginelli Reaction

Adsorption of 5-aminotetrazole and 3-aminotriazole on the surface of nanosized oxides of Al and Si–Ti, which are catalysts of the Biginelli reaction with the participation of aminoazoles, have been studied using the method of IR spectroscopy. It has been shown that 5-aminotetrazole and 3-aminotriazole interact with the Brønsted base centers on the oxide surface, with the behavior of aminoazole in the Biginelli reaction being determined by the coordination.     

Zirconium dioxide xerogel modified with powdered cellulose

Zirconium dioxide xerogel was synthesized in the presence of powdered cellulose. The samples obtained were studied in a model liquid-phase catalytic process of oxidative dehydrogenation of trimethylhydroquinone with atmospheric oxygen and in decomposition of hydrogen peroxide.     

TiO<Subscript>2</Subscript>-SiO<Subscript>2</Subscript> binary xerogels: Synthesis and characterization

Silica/titania binary xerogels were prepared by joint hydrolysis of the ingredients. Gels of various compositions were characterized by ¹H NMR spectroscopy, IR spectroscopy, and thermogravimetry. The spectral characteristics of binary systems differ considerably from mere superposition of the spectra of the two constituent compounds and the spectrum of a mechanical mixture. A feasibility was demonstrated for controlling the acid properties of binary oxide gels via varying the component mole ratio.