A new method of preparing 1, 2, 4-triazolinethione derivatives by directly sulfurating the corresponding triazoles is described. 4-(-Pyridyl)-1, 2, 4-triazoline-3-thione undergoes aminomethylation, cyanoethylation, and pyridylethylation at the nitrogen of the thioamide group. Replacement of the phenyl group in 4-phenyl-1, 2, 4-triazolinethione by -pyridyl, gives a compound closely resembling 1-phenyltetrazoline-5-thione in its properties.For Part VII see [1]. 相似文献
Urease was immobilized onto the glutaraldehyde cross-linked chitosan beads that were prepared under microwave irradiation. The activity and the yield of activity of immobilized urease was 10.83 U/g B and 47.7%, respectively. The conditions of urease immobilization were optimized. The properties of the immobilized urease were investigated and compared with that of the free enzyme. 相似文献
Comprehensive investigations have been performed by EPR and optical spectroscopy for Bi3GeO4 crystals doped with chromium ions. It is demonstrated that the known optical absorption spectrum for chromium ions, specifically,
the triplet in the region 600–900 nm has an analog in the EPR spectra — the center with electron spin S = 1. The spectrum is described by the spin-Hamiltonian with the parameters D = 550 G, E = 10 G, gxx = gyy = 1.915, gzz = 1.932. The EPR spectrum is dictated by Cr4+ incorporation at the germanium sites. Luminescence observed in the region 1.2–1.7 μm is also caused by transitions of Cr4+ with tetrahedral surroundings to germanium sites.
Original Russian Text Copyright ? 2005 N. V. Chernei, V. A. Nadolinnyi, N. V. Ivannikova, V. A. Gusev, I. N. Kupriyanov, V.
N. Shlegel, and Ya. V. Vasiliev
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Translated from Zhurnal Strukturnoi Khimii, Vol. 46, No. 3, pp. 444–450, May–June, 2005. 相似文献
Procedures for preparing polyfluorinated ethers H(CF2CF2)nCH2OR by alkylation of the corresponding telomeric alcohols H(CF2CF2)nCH2OH (n = 1–3) with alkyl halides and alkyl tosylates were examined. 相似文献
Four new zinc phosphates [Zn(HPO4)(C6H9N3O2)] (1), [Zn(HPO4)(C4H6N2)].H2O (2), [Zn2(HPO4)2(C14H14N4)].2H2O (3), and [Zn(HPO4)(C14H14N4)] (4) were synthesized in the presence of d-histidine, 1-methylimidazole, 1,4-bis(imidazol-1-ylmethyl)benzene (L1), and 1,2-bis(imidazol-1-ylmethyl)benzene (L2), respectively, and their structures were determined by X-ray crystallography. The inorganic framework of compounds 1, 2, and 3 is composed of vertex-shared ZnO3N and HPO4 tetrahedra that form four rings, which, in turn, are linked to generate a one-dimensional ladder structure. In 1 and 2 the organic groups (monoimidazole ligand) are located at each side of the ladders, while in 3 the bisimidazole ligand, 1,4-bis(imidazol-1-ylmethyl)benzene, links the ladders together to form a novel 2D structure. Compound 1 is the first zinc phosphate framework to be templated by an N-bonded chiral amino acid. In 4 the zero-dimensional four rings are joined together by the linear bridging ligand, 1,2-bis(imidazol-1-ylmethyl)benzene, to generate a one-dimensional framework with a new face-to-face structural motif. The 3D structure of compound 4 is stabilized by hydrogen-bonding, pi-pi interactions, and C-H...pi interactions. The approach of incorporating multifunctional ligands into zinc phosphate frameworks and linking the inorganic zinc phosphates subunits by an organic ligand provides opportunities for the design of new inorganic-organic open frameworks. 相似文献
New analogs of fragment 113–121 of the basic protein of myelin were synthesized: Phe-Ser-Trp-Gly-Ala-Glu-Gly-Gln-Arg, in which the phenylalanine in the first position has been replaced by L-alanine (V) and by D-phenylalanine (IX), and also a shortened analog with the deletion of the serine in the second position (XIII) and a lengthened analog with the insertion of glycine between the phenylalanine and tryptophan (XVII). In experiments on guinea pigs, one of the compounds obtained exhibited encephalitogenic activity. The circular dichroism spectra of compounds (I) and (IX), and also of some model compounds, have been studied in order to analyze the contribution of the aromatic amino acid residues to the dichroic absorption.
The chemical properties of 2-chloro-3-(-chloroethyl)-4,6-dihydroxypyridine (I) have been studied. It has been shown that this compound, which is relatively stable in acids and in neutral and, particularly, in alkaline media, readily splits off hydrogen chloride under mild conditions and is converted into derivatives of 2, 3-dihydro-5-azabenzofuran. The dehalogenation of I in an acid medium yielded 3-(-chloroethyl)-4, 6-dihydroxypyridine, which was converted into 4, 6-dichloro-3-(-chloroethyl)pyridine and into 6-chloro-4-methoxy-3-vinylpyridine. 相似文献
Summary The composition of a CO2 extract of the fruit of the pepperCapsicum annuum L. with respect to the main classes of compounds has been studied. A method has been developed for the extraction and quantitative determination of capsaicine.Krasnodar Scientific-Research Institute of the Food Industry. Translated from Khimiya Prirodnykh Soedinenii, No. 4, pp. 481–485, July–August, 1974. 相似文献
The intramolecular acylation of acid chlorides of ω-thienylalkanoic acids of various structures in the presence and absence of silica gel was investigated. The reaction of aluminum chloride etherate and the indicated acid chlorides with the surface groups of silica gel was studied by IR spectroscopy, and the role of the compounds formed on the surface in the reaction under consideration was discussed. A sequence of processes and a mechanism involving participation of the solid phase in the intramolecular acylation of acid chlorides of ω-thienylalkanoic acids are formulated. 相似文献
Free surface energy and acidity parameter of solid surfaces of polyepoxides used as anticorrosive coatings were measured. Formulations of epoxy resins with various curing agents were studied. The adhesion capacity of epoxy films to various metallic surfaces was evaluated. 相似文献