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1.
Four manganese(III) complexes (MnL1Cl, MnL2Cl, MnL42Cl, MnL52Cl) with a crowned salicylaldimine Schiff base ligand have been synthesized and employed as models to mimic hydrolase in the hydrolysis of p-nitrophenyl picolinate (PNPP). The kinetics and mechanism of catalytic PNPP hydrolysis have been investigated. The kinetic mathematical model of PNPP cleavage catalyzed by these complexes has been proposed. The effects of the ligand structure and crown ether ring in complexes, and the reactive temperature on the rate of catalytic PNPP hydrolysis have been also examined. The results show that compared with the crown-free analogous MnL3Cl and MnL62Cl, the crowned Schiff base manganese(III) complexes, MnL1Cl, MnL2Cl, MnL42Cl and MnL52Cl, exhibit more high catalytic activity, which follow the order: MnL1Cl >MnL2Cl >MnL42Cl >MnL52Cl >MnL3Cl >MnL62Cl; the pseudo-first-order-rate (kobs) for the PNPP hydrolysis catalyzed by the complex MnL1Cl containing three crown ether rings is highest among six complexes and is 1.81 times that of MnL3Cl, 1.49 × 103 times that of spontaneous hydrolysis of PNPP, respectively, at pH = 7.00, [S] = 2.0 × 10−4 mol dm−3.  相似文献   

2.
双(5-磺酸钠水杨醛)缩二胺水溶性席夫碱的合成   总被引:3,自引:0,他引:3  
王建华  杜军 《应用化学》1999,16(3):114-115
水杨醛及其衍生物与某些伯胺类化合物缩合形成的席夫碱及其金属螯合物,具有特殊的抗癌、抗炎、杀菌抑霉等活性,引起了各国化学家的广泛兴趣[1,2].对水溶性席夫碱金属螯合物的研究,国内外报道较少[3,4],其合成方法主要采用水杨醛衍生物、金属盐、胺类的“一...  相似文献   

3.
姚克敏  周文  鲁桂  沈联芳 《化学学报》2000,58(10):1275-1279
利用2,6-二氨基己酸(赖氨酸)具有两端不对称结构的-NH~2基,合成了一端与水杨醛,另一端与2,4-二羟基苯甲醛缩合形成空间结构不对称的异双Schiff碱及其与稀土元素配合物。以元素分析、热分析、摩尔电导、红外光谱、EPR以及^1HNMR,^1^3C-^1HCOSY谱、固体高分辨^1^3C谱等表征,研究了这类不对称Schiff碱的形成机理和配位方式。  相似文献   

4.
The new homodinuclear complexes of the general formula [Ln2L3(NO3)3] (where HL is newly synthesized 2-((2-(benzoxazol-2-yl)-2-methylhydrazono)methyl)phenol and Ln = Sm3+ (1), Eu3+ (2), Tb3+ (3a, 3b), Dy3+ (4), Ho3+ (5), Er3+ (6), Tm3+ (7), Yb3+ (8)), have been synthesized from the lanthanide(III) nitrates with the polydentate hydrazone Schiff base ligand. The flexibility of this unsymmetrical Schiff base ligand containing N2O binding moiety, attractive for lanthanide metal ions, allowed for a self-assembly of these complexes. The compounds were characterized by spectroscopic data (ESI-MS, IR, UV/Vis, luminescence) and by the X-ray structure determination of the single crystals, all of which appeared to be different solvents. The analytical data suggested 2:3 metal:ligand stoichiometry in these complexes, and this was further confirmed by the structural results. The metal cations are nine-coordinated, by nitrogen and oxygen donor atoms. The complexes are two-centered, with three oxygen atoms in bridging positions. There are two types of structures, differing by the sources of terminal (non-bridging) coordination centers (group A: two ligands, one nitro anion/one ligand, two nitro anions, group B: three ligands, three anions).  相似文献   

5.
侧链取代基含有氧原子的环戊二烯与双水杨醛邻环己二胺席夫碱混合配体的镧系化合物[(η5:η1-MeOCH2CH2C5H4)Ln][(μ:η-OC20H20N2O)]2[(η5-MeOCH2CH2C5H4)Ln](Ln=Sm(1),Dy(2)),[(MeOCH2CH2C5H4)2Yb]2(OC20H20N2O)(3),[(C4H7OCH2C5H4)2Dy]2(OC20H20N2O)(4)与三乙基铝体系催化甲基丙烯酸甲酯(MMA)的聚合,可以得到高分子量(粘均分子量Mη>100,000),窄分子量分布(Mw/Mn<3)的聚甲基丙烯酸甲酯(PMMA).不同茂环上的取代基及稀土元素使这类化合物形成了不同的分子结构,并且影响了它们的催化活性.化合物(3)具有较高的活性(转化率∶54.1%,Mη=287.1×103).考察了催化剂浓度,助催化剂浓度,聚合温度和时间对化合物(3)/Al(Et)3体系催化聚合反应的影响,最佳聚合条件为:60℃,24h,MMA∶催化剂∶助催化剂(摩尔比)=1000∶1∶10.利用核磁,凝胶渗透色谱仪(GPC)等对聚合物进行表征.  相似文献   

6.
Vogtle等发现,直链醚除具有类似冠醚配位各种金属离子的能力外,还弥补了冠醚的不足之处,如易合成、产率高、价廉等.我们曾报道过有关EPR工作.本文合成了2,4-二羟基苯甲醛缩二甘醇二胺(DHYDA)与镧系的新配合物.  相似文献   

7.
席夫碱及其络合物的可逆热致变色材料   总被引:15,自引:0,他引:15  
对具有可逆的热致变色的席夫碱及其络合物的分类、合成、变色机理以及发展前景等进行了回顾和探讨。  相似文献   

8.
甲酰基甲酸氨基硫脲席夫碱二价金属离子配合物的研究   总被引:14,自引:1,他引:14  
合成了甲酰基甲酸氨基硫脲席夫碱(H2FFTSC)的配合物.元素分析和摩尔电导等确定其组成为M(HFFTSC)_2·nH_2O(M=Co(Ⅱ),Ni(Ⅱ),n=2;M=Zn(Ⅱ),n=1;M=Mn(Ⅱ),Pb(Ⅱ),n=0)和Cu(FFTSC)·H_2O,红外吸收光谱等研究表明配体通过羧酸棍氧原子、甲亚胺氮原子和硫酮基(或硫醇基)的硫原子和金属离子配位.测试了配合物的杀菌活性.  相似文献   

9.
The properties of 12 new heterodi- and heterotrinuclear complexes having general formulae [Cu2Ln(L)2(NO3)(H2O)2](NO3)2·3H2O [where Ln = Pr (1), Nd (2), Sm (3) and Eu (4)], and [CuLn(L)(NO3)2(H2O)3MeOH]NO3·MeOH [where Ln = Gd (5), Tb (6), Dy (7), Ho (8), Ef (9), Tm (10), Yb (11) and Lu (12)], and their main ligand [L = C19H18N2O4Br2 = N,N’-bis(5-bromo-3-methoxysalicylidene)propylene-1,3-diamine] have been characterized by chromatographic analyses. The parameter of relative lipophilicity (R M0) of the tested compounds was determined experimentally by reversed-phase high-performance thin layer chromatography method with mixtures of methanol and water as a mobile phase. We also described interactions between chromatographed substances and various surfaces (silica—SiO2 and modified by hydrocarbon chains—RP-2, RP-8, RP-18 phases). This study also investigates the effect of pH of the mobile phase on the retention on the polar stationary phase. Thin layer chromatography combined with magnetic and electric field has been proposed as a complementary method for the determination of physicochemical properties of the investigated compounds. The chromatograms in the field and outside of it were developed simultaneously in three identical chromatographic chambers. One of them was placed in external magnetic field of 0.4 T inductivity, and the second in external electrical field. In magnetic and electric fields, retention of some complexes changed, which indicated that the presence of these fields influenced physicochemical properties of the compounds and their interactions with the stationary phase.  相似文献   

10.
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   

11.
Nine homobinuclear lanthanide complexes with macrocyclic Schiff base were prepared by condensing 2, 6-diacetylpyridine and 1, 3-diamino-2-hydroxypropane in the presence of template lanthanide metal ions. These complexes were characterized by elemental analysis, IR, molar conductance and magnetic susceptibility. The variable-temperature magnetic susceptibility (4-300 K) of complexes of Gd( Ⅲ ) and Dy( Ⅲ ) was determined. A satisfactory fit to theoretical curve derived from spin Hamiltonian operator was obtained using least-squares method. The exchange interaction parameters are J=-0.26 cm-1, g=1.98 and △=0.06 cm-1, Z.J'=-0. 21 cm-1,g'=1.33 for Gd( Ⅲ ) and Dy( Ⅲ ), respectively. The results indicate a very week antiferromagnetic interaction between Gd( Ⅲ )-Gd( Ⅲ ) and Dy( Ⅲ )-Dy( Ⅲ ) ions.  相似文献   

12.
《Analytical letters》2012,45(2):91-102
Abstract

The stability and ease of formation of some neutral salicylaldimine transition metal complexes has suggested that they may be gas chromatographed and find analytical applications. Thermal an of some bidentate Ni(II), Cu(II) and Zn(II) salicylaldimine comp has shown them to be thermally stable and volatile. Observations the gas chromatographic separation of some of these chelates is described, their favorable properties allow elution from glass a stainless steel columns with minimal decomposition under favorable conditions.  相似文献   

13.
二氨基硫脲与芳香醛(酮)反应,合成了3个三齿Schiff碱配体;配体与二苄基二氯化锡或三苄基氯化锡反应合成了6个未见文献报道的三齿配体杂环有机锡(Ⅳ)配合物,其结构经1H NMR, IR和元素分析表征.  相似文献   

14.
Five dinuclear lanthanide complexes [Ln2L2(NO3)2(OAc)4] · 2CH3CN [Ln = Gd ( 1 ), Tb ( 2 ), Dy ( 3 ), Ho ( 4 ), and Er ( 5 )] [L = 2‐((2‐pyridinylmethylene)hydrazine)ethanol] were synthesized from the reactions of Ln(NO3)3 · 6H2O with L and CH3COOH in the presence of triethylamine. Their crystal structures were determined. They show similar dinuclear cores with the two lanthanide ions bridged by four acetate ligands in the μ2‐η12 and μ2‐η11 bridging modes. Each LnIII ion in complexes 1 – 5 is further chelated by one L ligand and one nitrate ion, leading to the formation of a nine‐coordinated mono‐capped square antiprism arrangement. The dinuclear molecules in 1 – 5 are consolidated by hydrogen bonds and π ··· π stacking interactions to build a two‐dimensional sheet. Their magnetic properties were investigated. It revealed antiferromagnetic interactions between the GdIII ions in 1 and ferromagnetic interactions between the TbIII ions in 2 . The profiles of χmT vs. T curves of 3 – 5 reveal that the magnetic properties of 3 – 5 are probably dominated by the thermal depopulation of the Stark sublevels of LnIII ions.  相似文献   

15.
G 《物理化学学报》2009,25(11):2218-2224
Two new sporopollenin-immobilized Schiff bases, S-[N-(2-aminoetil) salicylaldiimino] and S-[N-(2-aminoetil) benzaldiimino], and their cobalt (Ⅲ) and nickel (Ⅱ) complexes, S-[N-(2-aminoetil) benzaldiimino] aquatriacetato cobalt (Ⅲ), S-[N-(2-aminoetil) salicylaldiimino] aquadiacetato cobalt (Ⅲ), S-[N-(2-aminoetil) benzaldiimino] diacetato nickel (Ⅱ), and S-[N-(2-aminoetil) salicylaldiimino] diacetato nickel (Ⅱ), were synthesized onto a chemically modified sporopollenin with ethylenediamine. The immobilized ligands and their metal complexes were characterized by thermal analysis and spectroscopic techniques such as infrared, ultraviolet-visible, and atomic absorption spectrometry. Immobilized Schiff base metal complexes, S-[N-(2-aminoetil) benzaldiimino] aquatriacetato cobalt (Ⅲ) and S-[N-(2-aminoetil) salicylaldiimino] aquadiacetato cobalt (Ⅲ), were used as ligand exchanger media to investigate ligand adsorption behavior of methylene blue (MB) with column technique. The result shows that the chelation of methylene blue with S-[N-(2-aminoetil) salicylaldiimino] aquadiacetato cobalt (Ⅲ) complex increases ligand adsorption capacity.  相似文献   

16.
合成了一种吡啶甲醛类Schiff碱铁配合物[Fe(PA2OPd)C12]Cl,并考察了配合物对环己烯绿色环氧化反应的催化活性及反应条件,结果表明:吡啶甲醛类Schiff碱铁配合物对环己烯的环氧化反应有比较高的催化活性及选择性.以过氧化氢为氧源、[Fe(PA2OPd)C12]Cl为催化剂、在pH=5.0左右的乙酸乙酯溶液中25℃反应6.0 h,环己烯转化率可达90.5%,环氧环己烷选择性可达97.2%.  相似文献   

17.
新型双核锌席夫碱配合物的合成及其结构表征   总被引:7,自引:0,他引:7  
新型双核锌席夫碱配合物的合成及其结构表征;席夫碱; 双核锌配合物; 合成; 谱学表征; 构象分析  相似文献   

18.
Schiff碱类芳香性金属配合物的合成及XPS研究   总被引:2,自引:0,他引:2  
用乙二胺(或丙二胺)缩乙酰丙酮Schiff碱三齿配体与咪唑(或苯并咪唑)及金属离子M(Ⅱ)配位,合成了12种Schiff碱类类芳香金属配合物,对这类配合物的X射线光电子能谱研究结果表明,配位后,金属离子的2p电子结合能降低,配位N原子的1s电子结合能增大;这类配全哦分子中的电荷移行径是以L→M为主,其配位键以σ键为主。  相似文献   

19.
新型双核席夫碱配合物的合成及谱学性质   总被引:1,自引:0,他引:1  
Eight novel binuclear tetradentate Schiff base complexes (M=Cu(Ⅱ),Ni(Ⅱ),Zn(Ⅱ)) are synthesized. The structure of complexes is two discrete Schiff base unit bridged. The complexes were condensed from series sub-stituent Ketones (5-chloro-2-hydroxybenzophenone, 5-methyl-2-hydroxy-benzophenone, 5-Bromo-2-hydroxybenzop- henone) and dialdehydes (5,5′-methylene-disalicylaldehyde) with the amino group of 1,2-diaminobenzene, and by Metal ion as template. The compounds were characterized by elemental analyses, FT-infrared spectra, Raman, 1H NMR, UV-vis electronic spectra, EPR spectra. The FT-infrared spectra and Raman spectra of complexes were compared and discussed. The UV-vis election spectra, 1H NMR and EPR spectra of complexes have also been attributed and minutely analyzed.  相似文献   

20.
The polymer-bound Schiff base ternary manganese complexes [PS-SalPhe-Mn-L (L = Phen, Bipy and 8HQ)] have been prepared from the polymer-bound Schiff base ligand, a manganese salt and the second ligand, such as 1,10-phenanthroline (phen), 2,2‘-bipyridyl (bipy) and 8-quinolinol (8HQ). The polymer-bound Schiff base ternary manganese complexes were characterized by means of infrared spectrometry and ICPAES. The catalytic activities of the complexes have been studied in the aerobic epoxidation of long-chain linear aliphatic olefins. It is shown that 1-octene or 1-decene can be directly oxidized by molecular oxygen when catalyzed by PS-SalPhe-Mn-L(L=Phen, Bipy and 8HQ), and 1,2-epoxy alkane can be afforded in these reactions.  相似文献   

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