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131.
A new pentacoordinated ferrous compound [TPAFeCl]+ (TPA = tris(2-pyridylmethyl)amine) was synthesized from the reaction between H3TPA(ClO4)3 and Fe(PnPr3)2Cl2 in MeCN. The unique trigonal bipyramidal [TPAFeCl]+ complex was characterized as a S = 2 high spin complex based on the crystallographic structure, magnetic susceptibility, 1H NMR spectrum and semi-empirical ZINDO/S calculations. Crystal of [TPAFeCl]2(FeCl4)(MeCN)2 was monoclinic with a = 12.019(2) Å, b = 27.550(5) Å, c = 14.138(2) Å, β = 94.168(3)°, V = 4668.9(13) Å3, space group C/c, and the unit cell contained a racemic mixture of Δ and Λ isomers with ferrous tetrachloride anion. 相似文献
132.
133.
An electrochemical method has been developed for determining the relative amounts of V(II) and V(III) in polyolefin catalysts prepared using aluminum alkyls and vanadium trichloride. The catalyst, usually obtained as a slurry in n-heptane, is titrated potentiometrically with ceric sulfate using a platinum indicator electrode. Under proper experimental conditions, 2 breaks are obtained, corresponding to the reactions V(II) →V(III) + e and V(III) →V(IV) + e. Interferences from other components of the catalyst are negligible. The method is useful for the analysis of both laboratory catalysts and grab samples taken from pilot plant reactors. 相似文献
134.
Nada F. Atta 《European Polymer Journal》2005,41(12):3018-3025
Polymeric films derived from thioflavin S were electrosynthesized on mild steel and silver electrodes in sulfuric acid and lithium perchlorate-containing aqueous solutions. The introduction of thioflavin S in an acidic solution protected the surface of steel from corrosion. The electrochemical behavior of the steel coated with a layer of poly(thioflavin) was examined by electrochemical impedance spectroscopy. The films exhibited a capacitive behavior and were semi-conductive in nature. Infra red reflectance measurements of the polymer films at the steel surface showed that the polymer structure retained the aromatic structure of the benzene and thiazole rings with the distinction of a nitrogen quinone vibrational band. Surface morphology of the polymer film was examined with scanning electron microscopy. The films are yellow, compact and dense when electrochemically formed onto steel surfaces when compared to a blue rather porous when formed onto silver electrode. The mechanism of electropolymerization of thioflavin is given and found similar to that of aniline with the possibility of metal chelation with the sulfur and/or nitrogen in the thiazole ring. 相似文献
135.
用葡聚糖凝胶层析分离制备牛血清蛋白(BSA)-茜素红S(ARS)配合物。在420和530 nm处用紫外可见吸收光谱法同时测定含有BSA-ARS配合物和茜素红S的联立方程为:A420=4.89×103cARS 3.06×104cBSA-ARS,A530=4.60×102cARS 2.29×104cBSA-ARS;正交试验选择了合适的分离条件:柱直径1.0 cm,柱长30.0 cm,凝胶用量1.3 g,最佳进样浓度为ARS:5×10-3mol/L、BSA:1.49×10-4mol/L,进样体积1.5 mL,洗脱流速0.33 mL/min,分离度为1.25;测定了纯BSA-ARS配合物紫外吸收光谱,最大吸收峰在530 nm。 相似文献
136.
AISI 304 Stainless Steel is widely used in different industrial fields because of its mechanical and corrosion properties.
However, its tendency to corrosion in presence of halide ions limits the applications. One strategy to improve the corrosion
resistance is the use of coatings barriers containing corrosion inhibitors in their formulation. The lanthanides present attractive
green and corrosion properties for the substitution of chromates, which are the most common substances used as corrosion protection.
However, these compounds are highly toxic, and an intense effort is being undertaken to replace them. Cerium is a good alternative
because of its relatively low cost and abundance. It fulfils the basics requirements for being considered an alternative inhibitor:
the ions form insoluble hydroxides and they present low toxicity. Inorganic and hybrid sol-gel coatings have been developed
to increase the corrosion resistance of metals and they provide an excellent vehicle for the incorporation of secondary phases
including particles and metal ions as cerium ions.
The aim of this work was to study the influence of the incorporation of cerium ions in hybrid silica sol-gel coatings deposited
on AISI 304 stainless steel as substrate as a potential replacement of chromate treatments. This system should combine the
barrier protection effect of silica coating with the corrosion inhibitor effect of the cerium ions inside the coatings. After
7 days of immersion in NaCl, coated substrates showed lower current densities than the bare steel, although the coatings produced
from Ce (III) salts experience a slight weakening in time and those obtained from Ce (IV) chemicals evidence an enhance in
the coating performance, probably due to the plugging of corrosion products in the defective areas of the film. 相似文献
137.
《印度化学会志》2021,98(10):100156
Corona virus disease 2019 (COVID-19) endemic has havoc on the world; the causative virus of the pandemic is SARS CoV-2. Pharmaceutical companies and academic institutes are in continuous efforts to identify anti-viral therapy or vaccines, but the most significant challenge faced is the highly evolving genome of SARS CoV-2, which is imparting evolutionary selective benefits to the virus. To understand the viral mutations, we have retrieved nine hundred and thirty-four samples from different states of India via the GISAID database and analyzed the frequency of all types of point mutation in all structural, non-structural proteins, and accessory factors of SARS CoV-2. Spike glycol protein, nsp3, nsp6, nsp12, N and NS3 were the most evolving proteins. High frequency point mutations were Q496P (nsp2), A380V (nsp4), A994D (nsp3), L37F (nsp6), P323L & A97V (nsp12), Q57H (ns3), D614G (S), P13L (N), R203K (N), G204R (N) and S194L (N). 相似文献
138.
Wolfgang Dietzsch Norman V. Duffy Aaron M. Lee Brian W. Skelton Allan H. White 《无机化学与普通化学杂志》2006,632(15):2419-2423
The consequences of replacement of the symmetrically chelate ligands in [M(E2CNR2)3] (E = S, Se) complexes of potential 32 symmetry by analogous mixed S,Se unsymmetrical chelates are explored for both small (M = Co) and large (M = In) metal atoms, and R = primary (Et) and secondary (iPr) alkyl substituents by way of low‐temperature single crystal X‐ray studies of [(Co(SSeCNEt2)3] ([Co(Se2CNEt2)3] also determined as datum), and [In(SSeCNR2)3], R = Et, iPr. The structure of [(iPr2N·CS·Se)2] is also recorded. 相似文献
139.
利用 2 ,3 丁二酮与丙二腈缩合形成双甲基双氰基环并内酰胺 ,经酸性水解得到双甲基环并内酯 ,然后和 (S) ( -) ( 1 苯基乙基 )胺反应生成 1,5 二甲基 2 (S) ( 1′ 苯基乙基 ) 2 氮杂 8 氧杂 -双环 [3 .3 .0 ]辛烷 3 ,7 二酮 ,通过元素分析、红外光谱、核磁共振氢谱和质谱对其结构进行了表征 .用X射线单晶衍射法测定了目标产物的晶体结构 ,结果表明 ,晶体属单斜晶系 ,P2 1 空间群 ,a =0 8777( 18)nm ,b =1 0 10 2 ( 2 )nm ,c =0 90 0 9( 18)nm ,β =118 75 ( 3 )° ,V =0 70 0 3 ( 2 )nm3 ,Dc=1 2 96g·cm-3 ,μ =0 0 89mm-1 ,F( 0 0 0 ) =2 92 ,Z =2 ,R1 =0 0 3 93 ,wR2 =0 0 95 5 . 相似文献
140.
Watanapokasin Yuwadee Nuchfoang Siriporn Nilwarangkoon Sirinun Sarangbin Somsak Kakizono Toshihide 《Applied biochemistry and biotechnology》2002,98(1-9):301-309
A bacterial strain, SWU-4, capable of using benzothiophene (BT) as a sole carbon and energy source was isolated from a petroleum-contaminated
site in Thailand and identified by 16S rRNA gene sequence analysis to be in the genus of Mycobacterium. The strain was Gram-positive, nonspore former, and grew at 50° C. Colonies of the strain on nutrient agar were rod-shaped,
smooth with a convex surface, slightly mucoid, and yellow pigmented. The thermophilic Mycobacterium sp. strain SWU-4 rapidly degraded 2% (w/v) BT at 50°C. Interestingly, this strain was able to degrade a wide variety of organosulfur
compounds including thiophene, bromo(α)thiophene, and 3-methylthiophene in liquid minimum medium at 50°C, which will be beneficial
for industrial applications. 相似文献