共查询到19条相似文献,搜索用时 62 毫秒
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合成了开链冠醚Schiff碱配体H2L(H2L=N,N′-双(邻羟苯亚甲基)-3,6-二氧杂-1,8-二氨基辛烷).详细研究了该配体在不同溶剂中和过渡金属离子存在下的荧光光谱,探讨了溶剂极性和不同金属离子对其荧光光谱的影响.结果表明:溶剂的极性和金属离子对其荧光性质有较大影响,随着溶剂极性的减小,配体的荧光增强,且谱峰发生蓝移.金属离子Zn2+、Cd2+对配体具有荧光增敏作用,Ni2+、Cu2+具有荧光猝灭作用.探讨了配体与金属离子结合的pH范围,结果显示最佳pH值为7—8. 相似文献
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研究了meso-四卟啉和meso-四卟啉的离解常数。TBPhP的离解常数为:pKa4=1.13.pKa3=1.88,pKA2=12.21;TTPS的离解常数为:pKa4=4.47,pKa3=6.26。外还发现了两卟啉的酸碱诱导聚合。 相似文献
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采用高效液相色谱法(HPLC)测定了桐油酸、3-正丁基-6-(1-癸烯酸甲酯基)-4-环己烯二酸(C23二酸甲酯)和3-正丁基-6-(1-癸烯酸基)-4-环己烯二酸(C22三元羧酸)的离解常数。用HPLC测定样品在不同pH(2.00~12.00)下的容量因子,通过最小二乘法计算出相应的离解常数。通过不同流动相比例下的离解常数计算出样品在纯水中的离解常数。实验得到的结果与用ACD/Lab软件计算得到的结果相近。桐油酸的pKa为4.79;C23二酸甲酯的pKa1为3.81,pKa2为5.78;C22三元羧酸的pKa1为3.68,pKa2为4.77,pKa3为5.73。 相似文献
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以苯硫脲基乙酸为端基的开链冠醚的合成及其性质研究 总被引:3,自引:0,他引:3
由NH4CNS、ClCH2COOH和开链冠醚桥联二芳胺在无水EtOH中回流,合成了3个以苯硫脲基乙酸为端基的开链冠醚,并经IR、^1HNMR,MS确证了其结构,。初步试验了其与金属离子 的络合性能。 相似文献
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The effect of crown ethers on the corrosion behavior of stainless steel (type 430) in 2M HCl solution was studied using weight loss and galvanostatic polarization methods. The inhibition efficiency was found to increase with increasing the concentration of the inhibitors and deceases with increasing the temperature. The polarization studies showed that crown ethers act as mixed-type inhibitors. The inhibiting effect of these compounds was interpreted in view of their adsorption on the metal surface. The adsorption of these compounds was found to obey Temkin adsorption isotherm. Surface examination and morphological studies were tested using scanning electron microscope (SEM) and energy dispersive X-ray (EDX). All the results achieved were compared and discussed. 相似文献
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Muhammad Ashram Ghassab M. Al-Mazaideh Wael Al-Zereini Ahmed Al-Mustafa Shehadeh Mizyed 《Journal of Sulfur Chemistry》2019,40(3):277-288
A series of new thiacrown ethers derived quinoline 7–9 were synthesized in good yield and in a simple way. Their transition metal ions complexation was studied using a conductometric method in acetonitrile at 25°C. Crowns 7 and 8 showed a continuous decrease in the molar conductances in their complexation with Ag+, Cu2+, Hg2+ and Zn2+ which begins to level off at a molar ratio of 1:1 crown to metal, indicating the formation of 1 stable 1:1 complex. On the other hand, crown 9 showed the formation of 1:1 complexes only with Ag+, Cu2+, Hg2+. The in vitro, a preliminary antimicrobial, antioxidant and cytotoxic effects on breast tumor cells were also reported. Five bacterial test strains were included in the present study. Antioxidant activity was measured in terms of the radical scavenging ability and decolorization of 1,1-Diphenyl-2-picrylhydrazyl (DPPH) radicals. Cytotoxic effect of thiacrown was evaluated using MDA MB-231 cell line (human breast adenocarcinoma, ATCC HTB-26). 相似文献
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介绍了冠醚化学的产生、发展及应用,详细介绍了:几种新型臂式冠醚及其超分子金属配合物的合成;取代冠醚及其金属配合物的合成及应用;新型氮杂冠醚及其金属配合物的合成及应用。并对冠醚化学的发展进行了展望。 相似文献
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四氢咔唑酮离解常数的光度法测定 总被引:1,自引:0,他引:1
研究了四氢咔唑酮在不同比例的乙醇.水混合溶剂中及不同酸度下的吸收光谱,提出了采用紫外分光光度法测定四氢咔唑酮在水中离解常数的方法.试验证明:在不同比例的乙醇.水混合溶剂中,四氢咔唑酮的离解常数与乙醇的体积分数存在良好的线性关系,通过外推至乙醇含量为零,可求得在实验条件下四氢咔唑酮在水溶液中的离解常数pKb为14.04. 相似文献
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Two novel chitosan derivatives—crosslinked chitosan dibenzo‐16‐c‐5 acetate crown ether (CCTS‐1) and crosslinked chitosan 3,5‐di‐tert‐butyl dibenzo‐14‐c‐4 diacetate crown ether (CCTS‐2)—were synthesized by the reaction of crosslinked chitosan with dibenzo‐16‐c‐5 chloracetate crown ether and 3,5‐di‐tert‐butyl dibenzo‐14‐c‐4 dichloracetate crown ether with the intent of forming polymers that could be used in hazardous waste remediation as toxic metal‐binding agents in aqueous environments. Their structures were confirmed with elemental analysis, infrared spectral analysis, and X‐ray diffraction analysis. In the infrared spectra of CCTS‐1 and CCTS‐2, the characteristic peaks of aromatic backbone vibration appeared at 1595 cm−1 and 1500 cm−1; the intensity of the N H and O H stretching vibration in the region of 3150–3200 cm−1 decreased greatly. The X‐ray diffraction analysis showed that the peak at 2θ = 20° decreased greatly in CCTS‐1 and CCTS‐2. The adsorption and selectivity properties of CCTS‐1 and CCTS‐2 for Pb2+, Cu2+, Cr3+, and Ni2+ were studied. Experimental results showed that the two crosslinked chitosan derivatives had not only good adsorption capacities for Pb2+, Cu2+, but also high selectivity for Pb2+, Cu2+ in the coexistence of Ni2+. For aqueous systems containing Pb2+, Ni2+, or Cu2+, Ni2+, CCTS‐1 only adsorbed Pb2+ or Cu2+. For aqueous systems containing Pb2+, Cr2+ and Ni2+, CCTS‐2 had high adsorption and selectivity properties for Pb2+. © 1999 John Wiley & Sons, Inc. J Appl Polym Sci 71: 2069–2074, 1999 相似文献
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J.S. Jaime Ferrer 《Electrochimica acta》2007,52(19):5773-5780
The autoprotolysis constant KHS of formic acid/water mixtures as solvent has been calculated from acid-base potentiometric titration curves. A correlation of the acidity scale pKHS of each medium versus pure water has been implemented owing to the Strehlow R0(H+) electrochemical redox function. The results show that formic acid/water mixtures are much more dissociated than pure water; such media are sufficiently dissociated to allow electrochemical measures without addition of an electrolyte. It has also been shown that for a same H+ concentration the activity of protons increases with formic acid concentration. For more than 80 wt.% of formic acid the acidity is sufficiently increased to locate the whole acidity scale pKHS in the super acid medium of the generalized acidity scale pHH2O. 相似文献
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