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91.
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Emel Yildiz Sadet Karabulut Neslihan S. Pinar Yusuf Karatas Figen Doran 《无机化学学报》2010,26(10):1743-1749
3,3,4,7-四羟基黄酮与1,3-二环己基碳二亚胺在4-二甲胺吡啶存在下反应,得到2,2-双(3,3,4,7-四羟基黄酮)1,3-二环己基碳二亚胺。三价金属离子与上述合成得到的配体螯合,对此四面体结构的双核Fe(Ⅲ)配合物的血液学及病理学数据进行了讨论,同时研究了合成的配体作为螯合剂清除鼠肝胰组织中超载的铁的能力。结果表明作为口服药其作为双齿配体的螯合能力与市售用于治疗地中海贫血的药物"去铁敏"相近。 相似文献
93.
Two coordination polymers of lanthanide complexes [(Dy)2(3,5-PDA)3(H2O)2]n 1 and [(Pr)2(3,5-PDA)3(H2O)3]n 2 (3,5-PDA = pyridine-3,5-dicarboxylate) have been synthesized under hydrothermal conditions. The prepared compounds were characterized by elemental analysis, IR and TG analyses and single-crystal X-ray structure determination. Complex 1 crystallizes in monoclinic, space group C2/c with a = 14.104(2), b = 11.1129(16), c = 15.086(2) , β =92.138(2)o, V = 2362.8(6) 3, Z = 4, C21H13Dy2N3O14, Mr = 856.34, Dc = 2.407 g·cm-3, F(000) = 1616, μ(MoKα) = 6.359 mm-1, the final R = 0.0422 and wR = 0.1016 for 2000 observed reflections with I 2σ(I). Complex 2 crystallizes in triclinic, space group P1 with a = 8.9441(13), b = 9.3959(14), c = 14.625(2), α = 98.065(2), β = 95.481(2), γ = 104.9130(10)o, V = 1164.7(3) 3, Z = 2, C21H15Pr2N3O15, Mr = 831.18, Dc = 2.370 g·cm-3, F(000) = 800, μ(MoKα) = 4.224 mm-1, the final R = 0.0355 and wR = 0.0731 for 4092 observed reflections with I 2σ(I). These polymers are constructed from the 3,5-PDA ligand but they exhibit different kinds of metal-organic framework structures. Complexes 1 and 2 are constructed from M-C-O zigzag corner-linked chains (M = Dy and Pr). In 1, the chains are composed of 8-coordinated DyIII centers, while the chains are made up of 8- and 9-coordinated PrIII centers in complex 2. These chains are cross-linked to each other by the pyridine rings of 3,5-PDA ligands, generating three-dimensional architectures. The magnetic behavior of compound 1 has been investigated, showing it exhibits antiferromagnetic interactions among the DyIII ions.a (Tianjin Key Laboratory of Structure and Performance for Functional Molecule, College of Chemistry and Life Science, Tianjin Normal University, Tianjin 300387, China) b (State Key Laboratory of Element-organic Chemistry, Nankai University, Tianjin 300071, China) 相似文献
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In order to bridge the gap between the supply and the demand of talent cultivation, the existing talent cultivation system of applied chemistry specialty is reformed and a new "113" talent cultivation system is guided by Outcome-Based Education (OBE) education. The advanced engineering education mode is adopted to provide students with an engineering education based on the background environment of the conceptual-design-implementation-operation (CDIO) process. The characteristic "three modernizations" education mechanism, namely, cooperative education, family training and personalized guidance, are implemented. By building a new system of "113" talents training, an engineering talent training environment is formed, which takes the family as a unit, the enterprise as the background, and the project as the carrier. The problem of separating the supply from the demand of talents training for applied chemistry specialty will be fundamentally solved. 相似文献
97.
含氯易挥发有机物(Cl-VOCs)是一类常见的大气污染物,可对生态环境和人类健康产生严重危害.相比其他治理方法,催化氧化法具有经济、高效的优势,其关键在于开发新型廉价的高性能催化材料.(Ce,Cr)_xO_2复合氧化物因具有强氧化性而表现出优异的催化性能,但仍需提高HCl选择性.研究表明,同时提高催化剂酸性和氧化性有助于促进Cl-VOCs降解.Nb_2O_5等固体酸金属氧化物同时具有丰富的表面酸性中心和一定的氧化性,被广泛应用于酸催化和氧化还原反应.将酸性氧化物和(Ce,Cr)_xO_2进行有效复合,有望同时改善催化剂的酸性质和氧化性,实现对Cl-VOCs的高效消除.本文选择Nb_2O_5作为固体酸载体,采用沉积-沉淀法制备了一系列不同质量比例的复合改性y(Ce,Cr)_xO_2/Nb_2O_5催化剂,考察了其对1,2-二氯乙烷(DCE)的催化降解性能,并利用XRD、UV-Raman、N2吸脱附、SEM、NH3-TPD和H2-TPR等手段表征了催化剂的结构-织构性质、形貌、表面酸性质以及氧化还原性能.通过优化活性组分组成,调控复合氧化物催化剂的物理化学性质,进一步提高其催化活性和选择性,并深入探讨了复合氧化物之间的相互作用机制以及氧化性中心与酸性中心二者的协同催化效应对Cl-VOCs催化降解性能的影响.DCE催化降解实验结果显示,随着(Ce,Cr)_xO_2/Nb_2O_5质量比(y值)的增加, y(Ce,Cr)_xO_2/Nb_2O_5催化剂对DCE的降解活性先增大后减小,生成副产物C2H3Cl的最大浓度逐渐降低,其中0.25(Ce,Cr)_xO_2/Nb_2O_5催化剂的本征催化活性最高.XRD图谱显示, y(Ce,Cr)_xO_2/Nb_2O_5复合催化剂上出现了TT相Nb_2O_5和立方相Ce O_2的特征峰;当(Ce,Cr)_xO_2与Nb_2O_5质量比小于0.25时,(Ce,Cr)_xO_2在Nb_2O_5表面高度分散.UV-Raman结果显示,复合催化剂上Nb_2O_5特征峰与单组分Nb_2O_5相比明显向低波数偏移,表明Nb_2O_5和(Ce,Cr)_xO_2之间存在较强的相互作用.N2吸脱附表征结果显示, y(Ce,Cr)_xO_2/Nb_2O_5为介孔结构,其织构性质变化与催化活性之间无直接联系.SEM照片显示,对于复合催化剂,(Ce,Cr)_xO_2颗粒高度分散在片状Nb_2O_5表面,二者的适当复合有利于其紧密接触并增强相互作用,进而充分发挥协同催化效应.NH_3-TPD结果显示,单组分Nb_2O_5具有最多的强酸中心数量和较高的酸强度,随着(Ce,Cr)_xO_2含量增加,强酸和总酸中心数量以及强/弱酸中心数量比值均逐渐减小.H_2-TPR结果显示, Nb_2O_5的氧化能力明显弱于(Ce,Cr)_xO_2,随着质量比y值增大, Nb_2O_5的δ峰向低温方向移动,并与(Ce,Cr)_xO_2的γ峰发生重叠,表明在两者界面处存在Nbm+–O–Cen+强相互作用,γ+δ峰的峰面积呈先增大后减小的变化趋势,其中0.25(Ce,Cr)_xO_2/Nb_2O_5的γ+δ峰面积最大.此外,复合催化剂中Cr6+物种的α峰面积逐渐增加,表明强氧化性的Cr6+物种含量逐渐增大.酸性中心与氧化中心各自单一方向的变化趋势与催化降解性能先增后减的变化趋势并不一致,表明二者之间的协同催化效应起着重要作用.综上,与单组分(Ce,Cr)_xO_2和Nb_2O_5相比, y(Ce,Cr)_xO_2/Nb_2O_5催化剂对DCE的本征催化降解活性显著提高,0.25(Ce,Cr)_xO_2/Nb_2O5_催化剂显示出最佳性能.催化剂酸性中心与氧化中心之间存在显著的协同催化效应:酸性中心有利于DCE的吸附和活化以及C–Cl键断裂得到质子化C_2H_3Cl;氧化中心则有利于C_2H_3Cl的深度氧化.合适的(Ce,Cr)_xO_2/Nb2O5比有利于(Ce,Cr)_xO_2颗粒在Nb_2O_5表面高度分散,促进酸性中心与氧化中心之间的协同催化效应,从而显著提高(Ce,Cr)_xO_2/Nb_2O_5复合催化剂的催化降解性能. 相似文献
98.
用停流FIA-分光光度法研究了铬(Ⅵ)-碘化钾动力学反应体系中铁(Ⅱ)和钒(Ⅳ)的协同诱导效应,以协同系数(D)表示二者相互作用程度的大小,在此基础上提出了一种新的动力学双组份同时测定的方法,本法可扩大前述方法的线性范围,并降低检测限,测定了模拟水样品中铁和钒的含量,结果满意。 相似文献
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100.
Inorganic crystalline solid electrolytes exhibit excep tional room-temperature ionic conductivities, giving them the potential to enable all-solid-state lithium (Li) - ion batteries. Developing new high-performance electrolytes is one of the most critical challenges to realize solid-state batteries, which requires understanding how chemistry facilitates fast ionic conduction and what the Li-ion migration mechanism is in in organic solid electrolytes. In this review, we aim to summarize recent fundamental research progress in Li-ion transport, including crystal structure, behavior of ion migration (i.e., single-ion jump and multi-ions cooperative migration), and the relationship between ion migration and microstructure. Generally, ion transport in crystalline structure can be categorized into vacancy and non-vacancy mechanism. For Li-ion conduction, the migration can be achieved through single-ion hopping and collective diffusion mechanism. For single-ion hopping mechanism, the diffusivity is determined by the depth of potential well (activation energy) and lattice dynamics;whereas in the later mechanism Li-ion moving from high potential to low potential could partially offset the energy required for Li-ion moving from low potential to high potential. By studying the collective diffusion from the perspective of local structures, it is believed that collective diffusion in fast ion conductor originates from the local 野dual Li-S/O冶 structure units, which can be characterized by the 野nearest Li-Li distance冶. Next, the paradigm of ion transport in solids is summarized. It is pointed out that most ion conductors follow Meyer-Neldel rule, where the activation energy and pre-exponential factor are mutual compensating. As a result, a balance should be adapted between these two values to achieve high Li-ion conductivity. However, for some fast ion conductors, the relationship does not follow the Meyer-Neldel rule (i.e., anti-Meyer-Neldel rule). Therefore, the physical significance of anti-Meyer-Neldel rule should be understood to develop next-generation lithium ion conductors. In the end, future perspectives and open questions are proposed to design and develop high-performance inorganic solid electrolytes. © 2021 Chinese Chemical Society. All rights reserved. 相似文献