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81.
Transformation of cyclohexa-2,4-diene-1,2-diylbis(methylene) diacetate to various carbasugars is described. Photooxygenation of a cyclohexadiene derivative gave a bicyclicendoperoxide, which was reduced with thiourea to [2-[(acetyloxy)methyl]cyclohexa-2,4-dien-1-yl]methyl acetate. Epoxidation of the remaining double bond followed by epoxide ring-opening and hydrolysis of the acetate groups gave one of the target hexols. The bicyclic endoperoxide was rearranged to a diepoxide with CoTPP. The diepoxide was reacted with sulfamic acid in acetic anhydride, resulting in the formation of a new branched carbasugar as well as in the formation of cyclitols with a 6-oxabicyclo[3.2.1]nonane skeleton. The mechanism of the formation of the products is discussed. The inhibition activity of six cyclitol derivatives was tested against α-glycosidase. 相似文献
82.
In this paper, the crosslinked polyester resin containing acrylic acid functional groups was used for the adsorption of uranium
ions from aqueous solutions. For this purpose, the crosslinked polyester resin of unsaturated polyester in styrene monomer
(Polipol 353, Poliya) and acrylic acid as weight percentage at 80 and 20%, respectively was synthesized by using methyl ethyl
ketone peroxide (MEKp, Butanox M60, Azo Nobel)-cobalt octoate initiator system. The adsorption of uranium ions on the sample (0.05 g copolymer
and 5 mL of U(VI) solution were mixed) of the crosslinked polyester resin functionalized with acrylic acid was carried out
in a batch reactor. The effects of adsorption parameters of the contact time, temperature, pH of solution and initial uranium(VI)
concentration for U(VI) adsorption on the crosslinked polyester resin functionalized with acrylic acid were investigated.
The adsorption data obtained from experimental results depending on the initial U(VI) concentration were analyzed by the Freundlich,
Langmuir and Dubinin–Radushkevich (D–R) adsorption isotherms. The adsorption capacity and free energy change were determined
by using D–R isotherm. The obtained experimental adsorption data depending on temperature were evaluated to calculate the
thermodynamic parameters of enthalpy (ΔH°), entropy (ΔS°) and free energy change (ΔG°) for the U(VI) adsorption on the crosslinked polyester resin functionalized with acrylic acid from aqueous solutions. The
obtained adsorption data depending on contact time were analyzed by using adsorption models such as the modified Freundlich,
Elovich, pseudo-first order and pseudo-second-order kinetic models. 相似文献
83.
Transition metal complexes of ditertiary aminomethylphosphine ligand, (Ph2PCH2)NCH3 [N,N‐bis(diphenylphospinomethyl)aminomethane], dppam, with metal ions which are Ag(I), Au(I), Cu(I), and Co(II) have been synthesized under nitrogen atmosphere by the Schlenk method. [Ag(dppam)2]NO3 ( 1 ), [Au(dppam)2]Cl ( 2 ), and [Cu(dppam)2]Cl ( 3 ) complexes have been isolated as colorless solids, whereas [CoCl2(dppam)] ( 4 ) complex as a blue solid. All complexes have been characterized by atomic absorption, FT‐IR, NMR (1H, 13C, 31P) spectroscopic, thermogravimetric/differantial thermal analysis (TG/DTA), and elemental analysis techniques. Antimicrobial activity of 1 , 2 , 3 , and 4 were studied in vitro on 13 bacteria and 4 yeasts. The cobalt(II) phosphine complex has shown the best antimicrobial activity in comparison with the other metal complexes. © 2005 Wiley Periodicals, Inc. Heteroatom Chem 16:484–491, 2005; Published online in Wiley InterScience ( www.interscience.wiley.com ). DOI 10.1002/hc.20145 相似文献
84.
Muhammad Nazrul Islam Burak Aksu Mehmet Güncü Markus Gallei Metin Tulu Tarik Eren 《Journal of polymer science. Part A, Polymer chemistry》2020,58(6):872-884
Bacterial infection is a global problem, especially resistance acquired by bacteria against to antibiotics; there is urgent need for the development of antibiotics. Here, we proposed dendron-grafted polymers via ring opening metathesis polymerization (ROMP) featuring different with tailored hydrophobicity/hydrophilicity and cationic charges. Dendritic oxanorbornene derivatives were synthesized having two and six carbon linkers and their corresponding random and block copolymers were prepared having pendant pyridinium salt moieties via ROMP. In total, 12 different water-soluble dendronized cationic polymers featuring hexyl pyridinium moieties were prepared and investigated. Six carbon linker possessing triple charge density and hexyl pyridinium functionality each repeating unit copolymers exhibited high antibacterial activity against Gram-positive bacteria (S. aureus). However, all the polymers were inactive against Gram-negative bacteria (E. coli). Most of the copolymers are non-hemolytic (>HC 50 = 1,000 μg/ml). It was also observed that, there is no significant effect between block copolymers and random copolymers keeping hydrophobicity and cationic charge density constant. Zeta potential was measured to investigate the mechanism in solution via the interaction of polymers with S. aureus, while scanning electron microscope (SEM) measurements image confirms damage of the bacterial cell wall after implementation of biocidal polymer. 相似文献
85.
Metin Gürses 《Letters in Mathematical Physics》1986,11(1):59-65
The Painlevé property of the vacuum Einstein field equations is investigated. It is observed that the field equations possess this property when spacetime admits commuting, nonnull two Killing vector fields. 相似文献
86.
The comment of Guseinov is irrelevant and also unjust. In contrast to his comment, we show that theobtained electric multipole moment values for some first-row diatomic molecules are original and better than his values(I.I. Guseinov, E. Akin, and A.M. Rzaeva, J. Mol. Struct. (Theochem) 453 (1998) 163) with respect to Hartree-Fockvalues. Moreover, it must be noted that all the formulas are cited in our paper (M. Orbay and T. Ozdogan, Commun.Theor. Phys. (Beijing, China) 35 (2001) 585) and corrigendum (M. Orbay and T. Ozdogan, Commun. Theor. Phys.(Beijing, China) 37 (2002) 768). 相似文献
87.
Ramazan Altundas Mariusz Krawiec William H. Watson Metin Balci 《Journal of chemical crystallography》1994,27(11):645-648
The photooxygenation of 2-amino-3-cyano-4,5,6,7-tetrahydro-benzo[b]thiopene1 was carried out in the presence of thiourea in order to reductively trap the intermediate; however, the rearranged compound
3-cyano-7-hydroxy-2-thio-2,4,5,6,7,7a-hexahydroindole2 was isolated. The structure, determined by X-ray crystallography, is described, and the mechanism for the formation of2 is discussed. 相似文献
88.
A regioselective approach was developed for the synthesis of dipyrrolo-diazepine derivatives. The synthetic route to dipyrrolo-diazepines first involves the synthesis of dipyrromethanes, followed by reaction of propargyl bromide in the presence of NaH to attach one alkyne functionality to the pyrrole nitrogen atom. Intramolecular heterocyclization with NaH in DMF between the alkyne functionality and pyrrole nitrogen atom gave the desired structures in good yields. 相似文献
89.
Ramazan Altundas Mariusz Krawiec William H. Watson Metin Balci 《Journal of chemical crystallography》1997,27(11):645-648
The photooxygenation of 2-amino-3-cyano-4,5,6,7-tetrahydro-benzo[b]thiopene1 was carried out in the presence of thiourea in order to reductively trap the intermediate; however, the rearranged compound 3-cyano-7-hydroxy-2-thio-2,4,5,6,7,7a-hexahydroindole2 was isolated. The structure, determined by X-ray crystallography, is described, and the mechanism for the formation of2 is discussed. 相似文献
90.
J. Metin D. Chatonier D. Avignant R. Chevalier J.C. Cousseins 《Journal of solid state chemistry》1984,55(3):299-305
A high-temperature phase with the formula has been characterized during the investigation of the CsFLuF3 system. This phase crystallizes in the monoclinic system with unit-cell dimensions a = 13.764(5) Å, b = 7.947(1) Å, c = 4.299(2)Å, β = 90.04(5)° and space group Cm (No. 8), Z = 2. The structure was solved by conventional Patterson and Fourier methods and refined by full-matrix least-squares techniques to a conventional R of 0.053 (Rw = 0.079) for 2038 independent reflections recorded on an automatic four-circle diffractometer. The structure may be regarded as built up of (Lu3F10)? layers that may be described as corner- and edge-shared LuF7 pentagonal bipyramids. These layers run parallel to the (001) plane. The structure extends along the third direction by cornersharing involving axial vertices of the pentagonal bipyramids. This three-dimensional framework delimits tunnels running parallel to the c direction where the Cs+ ions lie. The partial occupancies of both the Cs site and one out of the seven independent fluorine sites results in the nonstoichiometry. 相似文献