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Shu-lan Cai Fa-mei Feng Fu-an Liu 《Journal of Dispersion Science and Technology》2016,37(8):1170-1177
This study reports the synthesis method of a new aza-crown ether with an acetamide branch ligand, 2-(1,10-dioxa-4,7,13,16-tetraaza-cyclooctadec-4-yl)-acetamide (L), and determines the chemical composition of the cerium complex containing the aza-crown ether ligand by a new fluorescence spectrophotometric method. In the report, the cerium complex and its metallomicellar systems were used as catalysts in the hydrolysis of bis(4-nitrophenyl)phosphate ester (BNPP), and their catalytic activity was studied by the comparative method. The interaction between the metallomicelle and BNPP was proved by the fluorescence spectrum. The catalytic rate of BNPP hydrolysis was measured kinetically using the UV-Vis spectrophotometric method. The results indicated that the metallomicellar system of the anionic surfactant exhibited excellent catalytic function and relatively higher catalytic activity than that of the complex solution, the metallomicelle of nonionic and cationic surfactants, and the micelle provided an effective catalytic environment for the catalytic reaction. The experimental results also showed that the best acidity for the metallomicelle catalysis is pH 8.0, and the mono-hydroxy complex may be the real active species uaed as a catalyst in BNPP catalytic hydrolysis. The reaction mechanism was proposed on the basis of the research results. 相似文献
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《Journal of Dispersion Science and Technology》2013,34(4):337-341
The catalytic hydrolysis of bis(p-nitrophenyl) phosphate by lipophilic diaquo-(tetraamine)Co(III) complex in Brij35 micellar solution was investigated at 25°C and at pH ranging from 4.1 to 9.0. The results indicated that the Co(III) complex in micellar solution exhibited a great rate enhancement effect on the hydrolysis of bis(p-nitrophenyl) phosphate compared with the Co(III) complex in aqueous solution. This may be explained by the decrease in pK for the dissociation of water molecule of the Co(III) complexes in micellar solution. A kinetic scheme is suggested for elucidating the mechanism. 相似文献
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Δ3-lmidazoline-3-oxides were prepared by the reaction of corresponding aromatic Schiff bases with syn-2-bromoacetophenone oxime. 5,6-Dihydro-4H-1,2,5-oxadiazines were isolated as byproduct in some instances. 相似文献
44.
Synthesis and crystal structure of 1,1′-di(ethylpropionato)-2,2′-biimidazole, a macromolecular precursor 总被引:1,自引:0,他引:1
W. Mark Barnett Russell G. Baughman Harvest L. Collier William G. Vizuete 《Journal of chemical crystallography》1999,29(7):765-768
1,1,-Di(ethylpropionato)-2,2-biimidazole, C16H22N4O4, crystallizes from ice-cold ethanol in the space group P
, with a = 4.6742(9), b = 9.1119(13), c = 10.175(2) Å, = 96.22(1), = 96.29(2), = 97.53(1)°, and Z = 1. The molecule crystallizes with coplanar rings and the substituents assume a trans conformation with a center of inversion between the bridging carbon atoms. 相似文献
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A series of silicon containing poly(ester imide)s [PEIs] were synthesized using novel vinyl silane diester anhydride (VSEA)
and various aromatic and aliphatic dimines by two-step process includes ring-opening polyaddition reaction to form poly(amic
acid) and thermal cyclo-dehydration process to obtain poly(ester imide)s. VSEA was synthesized by using dichloro methylvinylsilane
and trimellitic anhydride in the presence of K2CO3 by nucleophilic substitution reaction. The PEIs were characterized by FTIR spectroscopy. The thermal properties of PEIs were
investigated by using differential scanning calorimetry (DSC) and thermogravimetric analysis (TG) methods. The prepared PEIs
showed glass transition temperatures in the range of 320–350°C and their 5% mass loss was recorded in the temperature range
of 500–520°C in nitrogen atmosphere. These had char yield in the range of 45–55% at 800°C. 相似文献
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藻酸双酯钠(ASD)与天青A(AA)反应可使天青A溶液褪色,最大褪色波长位于608 nm。应用光谱法研究了ASD与AA的作用机理,考察了反应体系中pH和AA/ASD摩尔比对ASD与AA相互作用的影响。通过理论模型测得AA与ASD最大结合数N=168,结合常数K=3.25×106。根据ASD-AA褪色体系建立了新的ASD测定方法,检测限为0.009 μg·mL-1,ASD的浓度在1~10 μg ·mL-1范围内遵守郎伯-比尔定律。该褪色体系操作简便,有较好的稳定性、选择性与准确度。据此直接测定了片剂中ASD的含量,得到满意结果。 相似文献
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