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聚合物键合Cu(Salen)的合成及其催化作用 总被引:1,自引:0,他引:1
一些简单的无机配合物已经广泛地用作氧载体和氧化催化剂,其中研究较多的是过渡金属卟啉和席夫碱(Schiff base)-过渡金属配合物。其中,席夫碱-过渡金属配合物的合成简单、易于控制配体的电子与立体因素,因而其催化性能的调变更具有灵活性,其分子氧体系已用于烯烃的环氧化和醇类的氧化,卟啉钴配合物-分子氧体系对硫醇的催化氧化研究已报道,其于席夫碱-金属配合物具有结合分子氧的特性和催经作用,以及高分子配合物催化剂的特点,我们合成了聚合物键合双水扬醛缩乙二胺合铜(Ⅱ),并将其用于催化分子氧氧化丙硫醇转化成二硫化物。 相似文献
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高分子担载水杨醛半胱氨酸希夫碱铜配合物催化氧化环己烯研究 总被引:2,自引:0,他引:2
研究了高分子担载水杨醛半胱氨酸希夫碱配合物(PS-Sal-Cys-M)催化氧化环己烯的性能,详细探讨了反应温度、反应时间、催化剂用量、反应添加剂对高分子担载水杨醛半胱氨酸希夫碱铜配合物催化氧化环己烯的反应性能的影响。研究表明,在常压下,用分子氧作作为氧化剂,不需要溶剂及共还原剂,环己烯可以被氧化生成环己烯醇和环己烯酮,产物的分离提纯比较容易,催化剂可以循环使用。 相似文献
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高分子担载水杨醛希夫碱钴配合物催化分子氧氧化环己烯性能研究 总被引:5,自引:0,他引:5
合成了聚苯乙烯担载的酪氨酸水杨醛希夫碱钴配合物,并研究了该高分子金属配合物对分子氧氧化环己烯的催化性能.探讨了反应温度、添加剂及反应时间对环己烯转化率和产物选择性的影响.结果表明,70℃时,以微量醋酸为添加剂,在催化剂的催化作用下,以常压氧气氧化环己烯,得到烯丙基位的氧化产物环己烯醇、环己烯酮和中间产物环己烯过氧化氢.催化剂经五次循环使用仍具有较高的催化活性.环己烯在该高分子配合物作用下的催化氧化遵循一个自由基反应历程,与经典的Haber-Weiss历程相一致. 相似文献
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聚类卟啉金属配合物 总被引:1,自引:0,他引:1
为模拟天然卟啉所具有的特殊生理活性,结构与性能各异的多种金属卟啉被合成并应用于许多领域。实际上,天然金属卟啉是在特定天然高分子-蛋白质营造的空穴中才能发挥其独特的性质,因此,类卟啉金属配合物的高分子化逐渐受到关注,并在载氧、催化、导电等领域取得重要成果。基于结合方式不同,高分子类卟啉金属配合物可分为高分子担载类卟啉金属配合物与聚类卟啉金属配合物。其中,后者以稳定的类卟啉环作为高分子链,不但使高分子骨架稳定,而且活性中心与类卟啉金属配合物之间有效间隔,同时活性中心相对密集,使其表现出较高的稳定性与活性。线形与平面型聚金属卟啉与金属酞菁表现出良好的导电性与催化活性;手性Salen席夫碱易于聚合得到线形或网状聚Salen希夫碱金属配合物,其表现出较强的催化活性、高ee值和可循环性。异双核聚类卟啉金属配合物也表现出较强的催化活化分子氧性能。 相似文献
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综述了近十几年来有关高分子担载希夫碱金属配合物的研究进展。此类配合物所采用的合成方法主要有:(a)含乙烯侧基的配体或金属配合物共聚;(b)小分子配体或配合物锚连于高分子载体。其主要性能为结合分子氧和催化活性。 相似文献
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研究了胆甾液晶二氮杂冠醚N,N′-双(胆甾-5-烯-3β-氧羰甲基)-1,10-二氮-4,7,13,16-四氧环十八烷(1)及其与Eu^3+的配合物(2),2一苯甲酸的混配物(3)的LB膜和荧光性质,结果表明:1,2和3在水溶液亚相液面形成稳定的单分子膜,但只有1的单分子面积受亚相pH的影响1,2和3的单分子膜都容易转移到石英基片上形成LB膜,其中2和3为X型,转移比分别为0.6和1.0,在LB膜 相似文献
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Mixed ligand complexes of Cu(II), Ni(II), Co(II) and Zn(II) formed with glycine and uracil or 2-thiouracil have been synthesized and characterized by elemental analysis, conductance, spectral (IR and electronic spectra) and magnetochemical measurements. Results show that glycine is bidentate in all cases; uracil behaves as a bidentate ligand in Cu(II) complex, coordinating through its one carbonyl oxygen and nitrogen, whereas in other cases it is only monodentate, coordinating only through nitrogen. With thiouracil, coordination occurs from carbonyl oxygen and one nitrogen in Cu(II) and Ni(II) complexes, but in the Co(II) complex coordination occurs from thionyl sulphur and nitrogen. In the Zn(II) complex it shows tridentate behaviour, coordinating through oxygen, sulphur and one nitrogen. Mixed Cu(II), Co(II) and Zn(II) complexes of uracil and of Ni(II) and Zn(II) with thiouracil are octahedral, whereas the mixed Ni(II) complex with uracil shows distorted tetrahedral geometry, and the mixed Co(II)-thiouracil complex is square planar. The mixed Cu(II)-thiouracil complex has a binuclear structure, with square planar arrangement around each copper atom. 相似文献
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The first azide(mu1,1)-bridged binuclear cobalt(II) complex with a chelated imino nitroxide radical, [Co2(immepy)2(N3)(4)].2EtOH, was structurally and magnetically characterized, where immepy = 4,4,5,5-tetramethyl-2-(6'-methyl-2'-pyridyl) imidazoline-1-oxyl. Five nitrogen atoms complete the coordination sphere of the Co(II) ion, showing a distorted trigonal bipyramid geometry. Two N(3)(-) anions act as bridges between cobalt ions in the mu1,1 coordination mode, resulting in a binuclear structure with an inversion center. Magnetic studies show that ferromagnetic couplings occurred between the adjacent cobalt(II) ions through N3(-)(mu1,1)) bridges, and antiferromagnetic couplings between the cobalt(II) ions and organic radicals. 相似文献
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Li DS Fu F Zhao J Wu YP Du M Zou K Dong WW Wang YY 《Dalton transactions (Cambridge, England : 2003)》2010,39(48):11522-11525
Two unique six-connected self-penetrating coordination polymers with a new (4(4).6(10).8) network topology, derived from the cross-linking of two 6(6)-dia subnets, were constructed from Ni(II) or Co(II) and two types of V-shaped tectons. The Ni(II) complex 1 shows an antiferromagnetic coupling via μ-carboxylate and μ-H(2)O pathways, whereas the Co(II) complex 2 exhibits the single-ion behavior in 300-34 K and then a ferromagnetic coupling at lower temperatures. 相似文献
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l-Penicillamine (Pen) has been investigated as a ligand for metalloprotein design by examining the binding of Co(II) to the sequence NH(2)-KL(Pen)EGG.(Pen)IG(Pen)GA(Pen).GGW-CONH(2). For comparison, we have studied Co(II) binding to the analogous sequence with Cys ligands, the ferredoxin maquette ligand IGA that was originally designed to bind a [4Fe-4S] cluster. The Co(II) affinity and UV-vis spectroscopic properties of IGA indicate formation of a pseudotetrahedral tetrathiolate ligated Co(II). In contrast, IGA-Pen showed formation of a pseudotetrahedral complex with Co(II) bound by three Pen ligands and an exogenous H(2)O. EXAFS data on both Co(II) complexes confirms not only the proposed primary coordination spheres but also shows six Co(II)-C(beta) methyl group distances in Co(II)-IGA-Pen. These results demonstrate that ligand sterics in simple peptides can be designed to provide asymmetric coordination spheres such as those commonly observed in natural metalloproteins. 相似文献
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Yang L Crans DC Miller SM la Cour A Anderson OP Kaszynski PM Godzala ME Austin LD Willsky GR 《Inorganic chemistry》2002,41(19):4859-4871
The synthesis and characterization of Co(II) and Co(III) 2,6-pyridinedicarboxylate (dipic(2-)) complexes are reported. Solid-state X-ray characterizations were performed on [Co(H(2)dipic)(dipic)].3H(2)O and [Co(dipic)(mu-dipic)Co(H(2)O)(5)].2H(2)O. Two coordination modes not previously observed in dipicolinate transition metal complexes were observed in these complexes; one involves metal coordination to the short C-O (C=O) bond, and the other involves metal coordination to a protonated oxygen atom. Solution studies, including paramagnetic NMR and UV-vis spectroscopy, were done showing the high stability and low lability of the Co(III) complex, whereas the Co(II) complexes exhibited ligand exchange in the presence of excess ligand. The [Co(dipic)(2)](2-) complex has pH dependent lability and in this regard is most similar to the [VO(2)dipic](-) complex. The [Co(dipic)(2)](2-) was found to be effective in reducing the hyperlipidemia of diabetes using oral administration in drinking water in rats with STZ-induced diabetes. Oral administration of VOSO(4) was used as a positive control for metal efficacy against diabetes. In addition to providing a framework to evaluate structure-function relationships of various transition metal complexes in alleviating the symptoms of diabetes, this work describes novel aspects of structural and solution cobalt chemistry. 相似文献
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Three new complexes of the formula M(2)L(2) derived from 2-(4-quinolyl)nitronyl nitroxide (4-QNNN) and M(hfac)(2) [M = Mn(II), Co(II), and Cu(II)], (4-QNNN)(2).[Mn(hfac)(2)](2) (1), (4-QNNN)(2).[Co(hfac)(2)](2).2H(2)O (2), and (4-QNNN)(2).Cu(hfac)(2).Cu'(hfac)(2) (3), were synthesized and characterized structurally as well as magnetically. Complexes 1 and 2 are four-spin complexes with quadrangle geometry, in which both the nitrogen atoms of quinoline rings and oxygen atoms of nitronyl nitroxides are involved in the formation of coordination bonds. For complex 3, however, the nitrogen atoms of quinoline rings are coordinated with Cu(II) ion to afford a three-spin complex, which is further linked to another molecule of Cu(hfac)(2) (referred to as Cu'(hfac)(2)) to form a 1D alternating chain. The magnetic behaviors of the three complexes were investigated. For complex 1, as the nitronyl nitroxides and Mn(II) ions are strongly antiferromagnetically coupled, consequently its temperature dependence of magnetic susceptibility was fitted to the model of spin-dimer with S = 2, yielding the intradimer magnetic exchange constant of J = -0.82 cm(-1). For complex 2, the temperature dependence of the magnetic susceptibility in the T > 50 K region was simulated with the model of two-spin unit with S(1) = 3/2 and S(2) = 1/2, leading to J = -321.9 cm(-1) for the magnetic interaction due to Co(II).O coordination bonding, D = -16.3 cm(-1) (the zero-field splitting parameter), g = 2.26, and zJ = -3.8 cm(-1) for the magnetic interactions between Co(II) ions and nitronyl nitroxides through quinoline rings and those between nitronyl nitroxides due to the short O.O short contacts. The temperature dependence of magnetic susceptibility of 3 was approximately fitted to a model described previously affording J(1) = -6.52 cm(-1) and J(2) = 3.64 cm(-1) for the magnetic interaction between nitronyl nitroxides and Cu(II) ions through the quinoline unit via spin polarization mechanism and the weak O.Cu coordination bonding, respectively. 相似文献
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Eisaku Hirasawa Kenji Tadano Shinichi Yano 《Journal of Polymer Science.Polymer Physics》1991,29(6):753-758
Thermal properties by differential scanning calorimetry, stiffness, and melt flow rate (MFR) were measured for the complex transition-metal (Zn(II), Cu(II), Mn(II), and Co(II)) salts of ethylene-methacrylic acid copolymer (EMAA) with 1,3-bis(aminomethyl)-cyclohexane (BAC). It was found that the strength of both ionic interactions of metal cations with carboxyl groups and coordination bonds of amino groups to metals differ among metal species. In particular, the complex Mn salts are weaker than the complex salts of the other transition metals, which corresponds with Irving-Williams series of stability constants of transition metal-ion complexes. Stiffness depends predominantly on the degree of crystallinity of ionic crystallites in ionic clusters, which depends on the ionic species. 相似文献
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I. A. Dereven’kov Thu Thuy Bui Thi D. S. Salnikov S. V. Makarov 《Russian Journal of Physical Chemistry A, Focus on Chemistry》2016,90(3):596-600
The kinetics of the reaction between one-electron-reduced cobalamin (cobalamin(II), Cb(II)) and the two-electron-oxidized form of vitamin C (dehydroascorbic acid, DHA) with amino acids in an acidic medium is studied by conventional UV–Vis spectroscopy. It is shown that the oxidation of Cbl(II) by dehydroascorbic acid proceeds only in the presence of sulfur-containing amino acids (cysteine, acetylcysteine). A proposed reaction mechanism includes the step of amino acid coordination on the Co(II)-center through the sulfur atom, along with that of the interaction between this complex and DHA molecules, which results in the formation of ascorbyl radical and the corresponding Co(III) thiolate complex. 相似文献
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Pandey S Das PP Singh AK Mukherjee R 《Dalton transactions (Cambridge, England : 2003)》2011,40(40):10758-10768
Using an acyclic hexadentate pyridine amide ligand, containing a -OCH(2)CH(2)O- spacer between two pyridine-2-carboxamide units (1,4-bis[o-(pyrydine-2-carboxamidophenyl)]-1,4-dioxabutane (H(2)L(9)), in its deprotonated form), four new complexes, [Co(II)(L(9))] (1) and its one-electron oxidized counterpart [Co(III)(L(9))][NO(3)]·2H(2)O (2), [Ni(II)(L(9))] (3) and [Cu(II)(L(9))] (4), have been synthesized. Structural analyses revealed that the Co(II) centre in 1 and the Ni(II) centre in 3 are six-coordinate, utilizing all the available donor sites and the Cu(II) centre in 4 is effectively five-coordinated (one of the ether O atoms does not participate in coordination). The structural parameters associated with the change in the metal coordination environment have been compared with corresponding complexes of thioether-containing hexadentate ligands. The μ(eff) values at 298 K of 1-4 correspond to S = 3/2, S = 0, S = 1 and S = 1/2, respectively. Absorption spectra for all the complexes have been investigated. EPR spectral properties of the copper(II) complex 4 have been investigated, simulated and analyzed. Cyclic voltammetric experiments in CH(2)Cl(2) reveal quasireversible Co(III)-Co(II), Ni(III)-Ni(II) and Cu(II)-Cu(I) redox processes. In going from ether O to thioether S coordination, the effect of the metal coordination environment on the redox potential values of Co(III)-Co(II) (here the effect of spin-state as well), Ni(III)-Ni(II) and Cu(II)-Cu(I) processes have been systematically analyzed. 相似文献
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Raja DS Bhuvanesh NS Natarajan K 《Dalton transactions (Cambridge, England : 2003)》2012,41(15):4365-4377
A novel water soluble ligand-bridged cobalt(II) coordination polymer has been synthesized by reacting the new ligand, 2-oxo-1,2-dihydroquinoline-3-carbaldehyde (isonicotinic) hydrazone (H(2)L) with Co(NO(3))(2)·6H(2)O and characterized by spectral, analytical and structural methods. Single crystal X-ray diffraction studies revealed that the Co(II) complex, {[Co(H(2)L)(H(2)O)(2)](NO(3))(2)·3H(2)O}(n) has a slightly distorted octahedral geometry around the central Co(II) ion; the ligand is coordinated through the ONO donor atoms to one Co(II) metal center and bridged through the pyridine nitrogen atom to another similar Co(II) center so as to form a one-dimensional polymeric unit. The interaction of the ligand and the complex with calf thymus DNA (CT-DNA) has been explored by absorption and emission titration methods, which revealed that the compounds could interact with CT-DNA through intercalation. The interactions of the compounds with bovine serum albumin (BSA) were also investigated using UV-visible, fluorescence and synchronous fluorescence spectroscopic methods. The results indicated that the complex exhibited a strong binding to BSA over the ligand. Investigation of the antioxidative properties showed that the polymeric Co(II) complex has a strong radical scavenging potency against hydroxyl radicals, 2,2-diphenyl-1-picrylhydrazyl radicals, nitric oxide and superoxide anion radicals. Further, the cytotoxic effect of the compounds examined on cancerous cell lines, such as human cervical cancer cells (HeLa), human laryngeal epithelial carcinoma cells (HEp-2), human liver carcinoma cells (Hep G2), human skin cancer cells (A431) and non-cancerous NIH 3T3 mouse embryonic fibroblasts cell lines showed that the complex exhibited substantial anticancer activity. 相似文献