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本文采用模型实验结合密度泛函理论B3LYP方法,研究了单核单齿配位、单核螯合配位、多核单齿配位以及多核双点配位Cr(Ⅲ)的氧化还原稳定性。结果显示,单核单齿配位体系的氧化还原稳定性低于单核螯合配位体系。模型实验与理论预测活性得出的结论一致。在此基础上,计算分析了多核Cr(Ⅲ)离子与羧基形成单齿配位结合和双点单齿配位结合后理论参数的差异。前线轨道能差表明这些配合物中Cr(Ⅲ)的氧化还原稳定性顺序为:单核螯合配位>单核单齿配位>四核双点单齿配位>三核单齿配位>二核单齿配位。研究结果将有益于控制皮革中Cr(Ⅵ)的产生。 相似文献
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以聚乙二醇(PEG)为配位体,首次合成了三价稀土金属镧与PEG的配位聚合物。实验测定了该配位聚合物的红外光谱、示差扫描量热谱(DSC)、热失重分析(TGA)和凝胶渗透色谱(GPC),并就配位反应、热分解以及配位前后分子流体力学体积的变化进行了讨论。 相似文献
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正本书简要概述了四十多年来国际和国内在平面多配位碳化合物领域的研究进展,主要介绍了平面多配位碳化合物的概念、发展、稳定策略及应用策略预测的结构和性质等,重点总结了作者在平面多配位碳化合物理论研究方面取得的系列成果,包括金属烃平面多配位碳、平面多配位碳过渡金属夹心化合物、平面多配位碳金属链夹心化合物、平面多配 相似文献
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稀土环己烷酸配合物合成及振动光谱研究 总被引:1,自引:0,他引:1
稀土羧酸配合物中,羧基配位方式是个有兴趣的问题。羧基采取单配位、螯合配位、对称桥式配位或单原子桥式(或螯合桥式)配位的那些方式,不但与稀土离子和羧酸结构,而且与配合物制备条件有关。不少研究发现某些配合物中,羧基可以同时存在多种配位方式。用振动光谱研究羧基的配位方式和配合物结构已引起广泛兴趣。环已烷酸(以下用HL和L分别代表酸及其阴离子)与稀土的配合物研究尚少,我们合成了它的十六种稀土的1∶3无水配合物,通过红外和拉曼光谱研究了羧基在各稀土配合物中的配合方式,配位多面体结构及配位键性质。 相似文献
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配位聚合物框架材料具有高的比表面积、丰富的孔结构和金属配位中心,一直以来被视为能源领域的潜在电极材料。传统配位聚合物框架材料电导率低,因此,如何设计并合成具有一定导电性的配位聚合物框架材料,满足能源及其相关领域对于材料电学性质的要求,成为配位聚合物框架材料领域的研究热点方向之一。本综述介绍了近年来导电二维配位聚合物框架材料的设计思路及电导率测量方法,并对这类材料的制备及其在能源转化及存储方面的应用进行了总结。最后,对二维高导电配位聚合物今后的研究和发展方向进行了展望。 相似文献
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钯在珠宝行业、工业催化、制药行业中应用广泛,也是汽车尾气排放装置触媒转换器中最重要的催化剂之一,但残留的钯离子对人体健康和环境有着极大的危害。近几年,人们对于钯离子残留的检测越来越重视,而配位型金属离子荧光探针是最方便且能快速检测离子的一种方法。本文根据配位方式的不同,综述了配位型钯离子荧光探针的研究进展,包括氮族元素配位(如N和P)的荧光探针、氧族元素配位(如O、S和Se)的荧光探针、同时与氮族和氧族元素配位的荧光探针、不饱和键配位的荧光探针以及聚合物荧光探针等。对不同配位方式、探针结构及对钯的检测效果进行了分析,希望能够为设计更灵敏、高效的配位型钯离子荧光探针提供启发。 相似文献
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E. A. Katayev G. V. Kolesnikov V. N. Khrustalev M. Yu. Antipin R. K. Askerov A. M. Maharramov K. E. German G. A. Kirakosyan I. G. Tananaev T. V. Timofeeva 《Journal of Radioanalytical and Nuclear Chemistry》2009,282(2):385-389
The synthesis and anion binding properties of a neutral macrocyclic receptor bearing H-bond donor coordination sites are described.
The anion binding studies by use of UV-vis and 99Tc NMR methods revealed that the receptor can coordinate perrhenate and pertechnetate in dimethylsulfoxide and chloroform
solutions with the relatively high binding constants, viz. log K
a > 4. The coordination mode of the perrhenate to the receptor was determined by a single-crystal X-ray diffraction analysis. 相似文献
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《Journal of organometallic chemistry》1989,375(1):C40-C42
The syntheses and electrochemistry of four novel polycobalticinium macrocyclic receptor molecules are reported. Preliminary anion coordination studies in one case reveal the receptor to be redox responsive to the binding of a Br− guest anion, shifting the respective cobalticinium reduction wave to more negative potentials. 相似文献
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This review describes the self-assembly of anion receptors from organic ligands and transition metal ions. These metal-assembled anion receptors can be synthesised from a number of different species; bidentate ligands with metals that prefer octahedral coordination geometries and monodentate ligands with metals that prefer square planar geometries are common. Anion binding transition metal helicates and systems where the coordination of metal ions results in the formation of an anion receptor by conformational locking are also reported. The effect of anion binding on the different properties of these complexes is discussed. 相似文献
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Mele A Metrangolo P Neukirch H Pilati T Resnati G 《Journal of the American Chemical Society》2005,127(43):14972-14973
A new heteroditopic receptor for alkali metal halides has been designed and synthesized. It is comprised of a well-established motif for cation binding and a motif for halogen-bonding-based anion recognition processes. The single-crystal X-ray structure of the complex between the heteroditopic receptor and sodium iodide is reported. Thanks to the cooperativity of metal coordination and the strong I-...I halogen bonding, the ion pair is fully separated. The boosting effect of the binding of the anion through halogen bonding on the coordination of the cation by the receptor has been proved also in solution by NMR experiments. The selectivity of the new heterotopic receptor toward different alkali metal halides has been tested by ESI mass experiments. 相似文献
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Boris S. Morozov Dr. Siva S. R. Namashivaya Marina A. Zakharko Dr. Aleksandr S. Oshchepkov Prof. Dr. Evgeny A. Kataev 《ChemistryOpen》2020,9(2):171-175
A new amido−amine cage receptor, which combines 1,8-anthracene diacarboxamide subunit and a polyammonium azamacrocycle, is reported. Bearing both the hydrogen bond donor and the acceptor binding sites, the receptor is able to bind phosphate selectively under neutral (pH 7.2) aqueous conditions. The recognition events for phosphate and dicarboxylates are accomplished by a fluorescence enhancement in the anthracene emission. As revealed by experimental and theoretical studies, phosphate and oxalate show different recognition modes. Phosphate demonstrates hydrogen bond acceptor properties, while the coordination of oxalate favours the protonation of the receptor. 相似文献
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Caillet-Saguy C Delepierre M Lecroisey A Bertini I Piccioli M Turano P 《Journal of the American Chemical Society》2006,128(1):150-158
Hemophore HasA is a 19 kDa iron(III) hemoprotein that participates in the shuttling of heme to a specific membrane receptor. In HasA, heme iron has an original coordination environment with a His/Tyr pair as axial ligands. Recently developed two-dimensional protonless (13)C-detected experiments provide the sequence-specific assignment of all but three protein residues in the close proximity of the paramagnetic center, thus overcoming limitations due to the short relaxation times induced by the presence of the iron(III) center. Mono-dimensional (13)C and (15)N experiments tailored for the detection of paramagnetic signals allow the identification of resonances of the axial ligands. These experiments are used to characterize the conformational features and the electronic structure of the heme iron(III) environment. The good complementarity among (1)H-, (13)C-, and (15)N-detected experiments is highlighted. A thermal high-spin/low-spin equilibrium is observed and is related to a modulation of the strength of the coordination bond between the iron and the Tyr74 axial ligand. The key role of a neighboring residue, His82, for the stability of the axial coordination and its involvement in the heme delivery to the receptor is discussed. 相似文献
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We have developed the tightest binding PPi receptor reported to date by a combination of metal coordination and hydrogen bonding interaction in water. 相似文献
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Hannon MJ Green PS Fisher DM Derrick PJ Beck JL Watt SJ Ralph SF Sheil MM Barker PR Alcock NW Price RJ Sanders KJ Pither R Davis J Rodger A 《Chemistry (Weinheim an der Bergstrasse, Germany)》2006,12(31):8000-8013
A platinum metal complex in which terpyridine joins estradiol (via an ethynyl link) to a platinum with a labile ligand (chloride) has been designed, synthesised and its X-ray crystal structure determined. The aim of this work was to link a targeting motif (in this case estrogen) to a metal-based biomolecule recognition unit (the platinum moiety). The target molecule: 17alpha-[4'-ethynyl-2,2':6',2'-terpyridine]-17beta-estradiol platinum(II) chloride (PtEEtpy) has been shown to bind to both human and bovine serum albumin (SA) and to DNA. FTICR mass spectrometry shows that the bimolecular units are in each case linked through coordination to the platinum with displacement of the chloride ligand. Circular dichroism indicates that a termolecular entity involving PtEEtpy, SA and DNA is formed. A range of electrospray mass spectrometry experiments showed that the PtEEtpy complex breaks and forms coordination bonds relatively easily. A whole cell estrogen receptor assay in an estrogen receptor positive cell (MCF-7) confirms binding of both EEtpy and PtEEtpy to the estrogen receptor in cells. The work demonstrates the concept of linking a targeting moiety (in this case estrogen) to a DNA binding agent. 相似文献
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Govor EV Lysenko AB Quiñonero D Rusanov EB Chernega AN Moellmer J Staudt R Krautscheid H Frontera A Domasevitch KV 《Chemical communications (Cambridge, England)》2011,47(6):1764-1766
Chloride-centered hexanuclear hydroxopyrazolate reveals potential as a receptor of halomethane and halometallate species and as a molecular building block for coordination polymers. 相似文献
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A new self-folding cavitand has been assembled through metal coordination to give a thermodynamically stable ditopic receptor of nanosize dimensions which has been used in the reversible binding of di-alkylammonium and n-alkylammonium salts. 相似文献