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排序方式: 共有139条查询结果,搜索用时 125 毫秒
81.
Mitra Ghassemzadeh Forough Adhami Majid M. Heravi Abas Taeb Soheila Chitsaz Bernhard Neumüller 《无机化学与普通化学杂志》2001,627(5):815-819
The reaction of [(Ph3P)2CuCl]2 with 4‐amino‐6‐methyl‐1,2,4‐triazine‐thione‐5‐one (AMTTO, 1 ) in methanol and further recrystallization from methanol/acetone solution gives [(C4H4N3SON(=CMe2)Cu(PPh3)2Cl] ( 2 ) as a neutral complex. [(C4H4N3SON(=CMe2)Ag(PPh3)2]NO3 ( 4 ) can be obtained in excellent yield by the reaction of [(AMTTO)2Ag]NO3 ( 3 ) with triphenylphosphane in methanol/acetone. Both complexes were characterized by infrared spectroscopy, elemental analyses as well as by X‐ray diffraction studies. Crystal data for 2 at –80 °C: space group P1 with a = 1233.8(1), b = 1389.7(1), c = 1417.1(1) pm, α = 89.36(1)°; β = 65.10(1)°, γ = 65.95(1)°, Z = 2, R1 = 0.0582 and for 4 at –80 °C: space group P1, with a = 1193.3(1), b = 1308.5(1), c = 1385.3(1) pm, α = 94.69(1)°, β = 109.14(1)°, γ = 93.42(1)°, Z = 2, R1 = 0.0716. 相似文献
82.
83.
Dr. Lingling Zhang Haiyang Cui Dr. Gaurao V. Dhoke Dr. Zhi Zou Dr. Daniel F. Sauer Dr. Mehdi D. Davari Prof. Ulrich Schwaneberg 《Chemistry (Weinheim an der Bergstrasse, Germany)》2020,26(22):4974-4979
Copper efflux oxidase (CueO) from Escherichia coli is a special bacterial laccase due to its fifth copper binding site. Herein, it is discovered that the fifth Cu occupancy plays a crucial and favorable role of electron relay in bioelectrocatalytic oxygen reduction. By substituting the residues at the four coordinated positions of the fifth Cu, 11 beneficial variants are identified with ≥2.5-fold increased currents at −250 mV (up to 6.13 mA cm−2). Detailed electrocatalytic characterization suggests the microenvironment of the fifth Cu binding site governs the electrocatalytic current of CueO. Additionally, further electron transfer analysis assisted by molecular dynamics (MD) simulation demonstrates that an increase in localized structural stability and a decrease of distance between the fifth Cu and the T1 Cu are two main factors contributing to the improved kinetics of CueO variants. It may guide a novel way to tailor laccases and perhaps other oxidoreductases for bioelectrocatalytic applications. 相似文献
84.
Davari Hadi Goshayeshi Hamid Reza Öztop Hakan F. Chaer Issa 《Journal of Thermal Analysis and Calorimetry》2020,140(6):2605-2614
Journal of Thermal Analysis and Calorimetry - This paper presents a novel study on the performance of closed-loop oscillating heat pipe (CLOHP) using iron oxide (Fe3O4) as the working fluid for... 相似文献
85.
Lotf Ali Saghatforoush Soheila Sanati Robabeh Mehdizadeh Mohammad Hasanzadeh 《Superlattices and Microstructures》2012
Cadmium hydroxide (Cd(OH)2) microcrystals were synthesized in ethanol–water medium by using cadmium chloride as cadmium source and 1,10-phenanthroline as complexation agent under solvothermal condition. The sample was characterized by FT-IR, X-ray diffraction (XRD), scanning electron microscopy (SEM) and TEM. The as-prepared Cd(OH)2 product were transformed to hexagonal CdO nanocubes by thermal treatment in air at 500 °C. The possible growth mechanism for the formation of different morphologies at basic medium has been proposed. DPV experiments were carried out for the simultaneous determination of norfloxacin and lomefloxacin in the acetate buffer solution with pH 4.5. 相似文献
86.
Kobra Omidfar Solmaz Kia Soheila Kashanian Malihe Paknejad Afsaneh Besharatie Susan Kashanian Bagher Larijani 《Applied biochemistry and biotechnology》2010,160(3):843-855
Digoxin is widely used as a cardiac glycoside drug in the treatment of various heart conditions. Because it is a toxic drug, it should be regularly monitored in the serum of patients under treatment. In this study, colloidal nanogold is synthesized and the preparation of nanogold-labeled monoclonal antibody probe to digoxin is described under optimal conditions. In addition, an immunochromatographic (IC) method for digoxin analysis employing nanogold-labeled probe is developed. With this technique, it requires only 5 min to complete the quantitative detection of digoxin. The detection time is decreased 20–30 times in comparison to radioimmunoassay (RIA). The sensitivity to digoxin was about 2 ng/ml by naked eye, which is within the therapeutic and toxic ranges of digoxin. The results of serum samples obtained by IC strip were in agreement with those obtained by RIA. The IC strip was sufficiently sensitive and accurate to be used for the rapid detection of digoxin in serum samples. 相似文献
87.
88.
The Theoretical and Experimental Studies on Oxidation of Straight Chain Amino Acids in Moderately Concentrated Sulfuric Acid Medium
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Homayoon Bahrami Gholamreza Jaferian Mehdi D. Davari Mansour Zahedi Ali Akbar Moosavi‐Movahedi 《国际化学动力学杂志》2016,48(11):647-659
The kinetics of the permanganic oxidation process of some straight chain amino acids in moderately concentrated sulfuric acid medium have been investigated using a spectrophotometric technique. Conclusive evidences have proven autocatalytic activity of Mn(II) for these reactions. It is determined that even and odd effects of the number carbon atom in a carbon chain are annihilated when it's the number of carbon atoms is increased more than of three in a noncatalytic oxidation pathway. Thus, rate constants belonging to glycine, l ‐α‐amino‐n‐butyric acid, l ‐norleucine, and l ‐α‐amino‐n‐heptanoic acid satisfy Taft's equation involving the induction factor in the noncatalytic pathway, whereas l ‐α‐amino‐n‐heptanoic acid has an odd number of carbon atom in its chain carbon. On the other hand, in the catalytic pathway, rate constants satisfy Taft' equation including inductive and steric factors, when rate constants belonging to amino acids with an even number of carbon atoms are separated from those with an odd number of carbon atoms. The oxidation process of amino acids in the noncatalytic pathway and those with the even number of carbon atoms in the carbon chain in the catalytic pathway speeds up by an increase in the length of chain that is accompanied with an increase in the carbon chain's electron‐donating characteristic. On the other hand, an increase in the length of the carbon chain is accompanied with more steric hindrance, which counteracts its electron‐donating character, thereby decreasing reaction rate in the catalytic pathway. Finally, amino acid–Mn(II) complexes were studied using a density functional theory method. Results obtained show that such a complex is less stable than reactants, namely it is formed in an endothermic reaction. The number and strength of hydrogen bonding belonging to amino acid is more than those of the amino acid–Mn(II) complex. Besides, it has been illustrated that natural bond orbital analysis and molecular orbital calculations satisfy the findings. 相似文献
89.
Synthesis,characterization and application of graphene palladium porphyrin as a nanocatalyst for the coupling reactions such as: Suzuki‐Miyaura and Mizoroki‐Heck
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The palladium(II)‐coordinated 5,10,15,20‐tetrakis‐(4‐hexyloxyphenyl)‐porphyrin as a macrocyclic palladium complex was covalently grafted to the surface of graphene oxide (denoted as GO‐CPTMS@Pd‐TKHPP). GO‐CPTMS@Pd‐TKHPP was characterized using microscopic and spectroscopic techniques for confirmation of functionalization. The synthesized catalyst was checked in the Suzuki‐Miyaura and the Mizoroki‐Heck coupling reactions. The catalyst is very easy to handle, environmentally safe and economical. Also, this catalytic system shows high catalytic activity and the yields of the products are excellent. Moreover, the suggested catalyst was reusable for five runs with no significant decrease in catalytic activity. 相似文献
90.
Graphene oxide (GO) was doped to eutectic uniaxial nematic liquid crystals (NLCs) (E5CN7) with different percentages to improve the physiochemical properties of NLCs effectively. GO shifts the N-I phase transition temperature to higher values. It has been observed that increasing GO concentration up to 0.75% increases the N-I phase transition temperature substantially while further increase of GO concentration results in an inverse trend. The GO/E5CN7 non-covalent interactions change the N-I phase transition. The contribution of several terms such as anchoring and polarisation effects on N-I phase transition was quantified as well. The results suggest that the size is an important contributor to GO and liquid crystal interaction. The results show that E5CN7@GO composites may act as promising candidates to enhance the efficiency of room temperature devices. 相似文献