空间不对称席夫碱铜配合物的合成及其与金属卟啉的反应

合成了新型具有空间不对称四齿席夫碱配合物 (Cu[XBP- PHEN- 4 - CHO- Im] ,X=H,Cl,Br,CH3 ;Cu[CBP- PHEN- 2 - CHO- Im] ,C=Cl)。并进行了红外、元素分析、质谱等表征。研究了此类席夫碱铜配合物在二氯甲烷溶剂中与四苯基卟啉锌 (Zn TPP)反应的电子光谱 ,结果表明 ,此类席夫碱铜 ( )配合物可以与锌卟啉发生轴向配位反应。     

氨基酸席夫碱的合成及性质研究

合成了5种氨基酸席夫碱Sal-Gly(甘氨酸席夫碱)、Sal-Glu(谷氨酸席夫碱)、Sal-Met(甲硫氨酸席夫碱)、Sal-Tyr(酪氨酸席夫碱)、Sal-Arg(精氨酸席夫碱)及其金属锌离子配合物共10种化合物.用元素分析、核磁共振、红外光谱、紫外-可见光谱等手段对其组成的结构进行表征.以Sal-Tyr-Zn为主体,咪唑(1),1-甲基-咪唑(2),2-乙基-4-甲基咪唑(3),吡唑(4),4-碘苯胺(5),DABCO(1,4-重氮双环[2,2,2]辛烷)(6),邻苯二胺(7)和1,2-环己二胺(8)为客体,进行配位相互作用研究.选取大肠杆菌作为抑菌菌种,研究了氨基酸席夫碱的抑菌能力.结果表明,氨基酸席夫碱配体及金属锌配合物对大肠杆菌均有抑菌活性,配体的抗菌活性随氨基酸残基的增大而减小.金属锌配合物的抑菌活性大于其所对应的氨基酸席夫碱配体的抑菌活性,活性最大的则为Sal-Arg-Zn.     

空间不对称席夫碱铜配合物的合成及其与金属卟啉的反应

合成了新型具有空间不对称四齿席夫碱配合物(Cu[XBP-PHEN-4-CHO-Im],X=H,Cl,Br,CH₃;Cu[CBP-PHEN-2-CHO-Im],C=Cl)。并进行了红外、元素分析、质谱等表征。研究了此类席夫碱铜配合物在二氯甲烷溶剂中与四苯基卟啉锌(ZnTPP)反应的电子光谱,结果表明,此类席夫碱铜(Ⅱ)配合物可以与锌卟啉发生轴向配位反应。     

吡啶酰胺基苯胺类化合物的水杨醛席夫碱及其铜(Ⅱ)配合物的合成及晶体结构

本文以水杨醛和N,N′-(2-胺基苯基)-2,6-二甲酰亚胺吡啶进行缩合得到席夫碱化合物L,然后与CuCl2.2H2O分别在甲醇、乙醇溶液中进行配位反应;在进行配位反应中,化合物L的一端酰胺键发生醇解,分别被甲醇,乙醇取代,从而,得到了吡啶酰胺一端被甲醇,乙醇取代的席夫碱铜(Ⅱ)单核配合物1和2。用元素分析,FTIR和X-射线单晶衍射进行了表征。结果表明,化合物L属于三斜晶系,空间群Pī,配合物1和2都属于单斜晶系,空间群都为P21/c,配合物1和2均为单核配合物。配合物2通过弱相互作用形成二聚体。     

氨基酸水杨醛席夫碱与铜(Ⅱ)配合物的合成及其抗菌活性和稳定性、结构间的关系

氨基酸水杨醛席夫碱与铜（Ⅱ）配合物的合成及其抗菌活性和稳定性、结构间的关系毕思玮＊刘树祥（曲阜师范大学化学系，曲阜２７３１６５）关键词：氨基酸水杨醛席夫碱铜（Ⅱ）稳定常数抗菌活性实验部分将１０ｍｍｏｌ氨基酸和０．５６ｇ（１０ｍｍｏｌ）ＫＯＨ溶于热的９...     

水杨醛缩精胺及其配合物的合成与生物活性

Ｏ ,Ｏ 二甲基硫代磷酰胺 (简称精胺 )是合成农药甲胺磷的中间体 ,我们以精胺、水杨醛为原料 ,合成了水杨醛缩精胺席夫碱及其铜、镍、锌配合物 (下图 )。生物活性实验表明 ,该席夫碱配体及其配合物具有较好的抑制超氧离子的功效和消灭红蜘蛛的生物活性。1　实验部分1 1　试剂与仪器所用试剂为ＡＲ或ＣＰ ,精胺用前经硅胶柱色谱纯化处理。化合物的Ｃ、Ｈ、Ｎ用Ｐ Ｅ2 4 0自动元素分析仪、铜用碘量法、镍、锌用ＥＤＴＡ法测定。Ｐ Ｅ983富立叶红外光谱仪 ,ＫＢｒ压片法 ;Ｐ Ｅｌａｍｂｄａ 7紫外分光光度计 ,无水甲醇作溶剂。Ｖａｒｉａｎ Ｘ…     

三羟甲基氨基甲烷水杨醛类席夫碱质子转移异构化的理论研究

采用密度泛函(DFT)中的B3LYP方法,在6-311+G(d,p)基组水平上对三羟甲基氨基甲烷水杨醛席夫碱气相、水溶剂及甲醇溶剂中的分子内质子转移和衍生席夫碱的互变异构反应机理进行了计算研究,获得了反应焓、活化能、活化吉布斯自由能和质子转移反应的速率常数等参数.液相计算采用Onsager模型.结果表明,不论在气相、水溶剂还是甲醇溶剂中,三羟甲基氨基甲烷水杨醛席夫碱(L3=H,L5=H)烯醇亚胺式异构体R1和醌型的酮烯胺异构体P1可以共存,但以苯环型的烯醇亚胺式R1为主要形式.当由苯环型的烯醇亚胺R1向醌型的酮烯胺P1分子内质子转移时活化能较低,室温常压下反应容易进行.水和甲醇溶剂对异构化反应影响较小.当—NO2,—OMe取代生成衍生席夫碱时(L3=H,L5=NO2;L3=OMe,L5=H),结果表明,苯环型的烯醇亚胺式和醌型的酮烯胺式异构体都能共存,质子转移异构化反应的活化能垒也较低.     

双亲性席夫碱铜(Ⅱ)配合物的合成及苯甲醇的催化氧化

铜配合物;双亲性席夫碱铜(Ⅱ)配合物的合成及苯甲醇的催化氧化     

手性席夫碱-铜（Ⅱ）与-钒氧（Ⅱ）配合物的合成及其在不对称氧化反应中的应用

手性席夫碱-铜（Ⅱ）与-钒氧（Ⅱ）配合物的合成及其在不对称氧化反应中的应用;席夫碱-钒氧配合物;席夫碱-铜配合物;不对称氧化偶合;联萘酚;氨基酸;β-萘酚     

卟啉环上的亲核取代：2-(2-萘酚)-5,10,15,20-四苯基卟啉的合成

为了制备2-取代卟啉，研究了2-硝基-5,10,15,20-四苯基卟啉1及其镍2，铜3，锌4配合物与2-萘酚钠在不同溶剂中的反应。在2-萘酚中，150℃的温度下反应，分别得到2-(2-萘酚)-5,10,15,20-四苯基卟啉5 （72%）, 及其镍(II) 6（78%）, 铜(II) 7（81%）, 锌(II) 8（65%）配合物。在其它质子性溶剂如一缩二乙二醇和一缩二乙二醇单甲醚中反应，得到相同的产物。当在非质子性溶剂DMF，150 ℃的温度下反应，除了得到5 (70%)，6 (34%)，7 (54%), 8 (50%)外，还分别得到微量2-(2-萘氧基)-5,10,15,20-四苯基卟啉9, 及其镍(II) 10（40%）,铜(II) 11（18%）, 锌(II)12 （2%）配合物。但室温下，无论用DMF还是DMSO做溶剂，均只得到5，6，7，8。卟啉1-4与萘酚钠的反应比与苯酚钠反应快，C-C键产物5-8的形成被认为是通过S_RN1机理进行的。     

Antioxidant activity of bovine serum albumin binding amino acid Schiff-bases metal complexes

Glutamic acid-salicylaldehyde Schiff-base metal complexes are bound into bovine serum albumin (BSA),which afforded BSA binding Schiff-base metal complexes (BSA-SalGluM,M=Cu,Co,Ni,Zn).The BSA binding metal complexes were characterized by UV-vis spectra and Native PAGE.It showed that the protein structures of BSA kept after coordinating amino acid Schiff-bases metal complexes.The effect of the antioxidant activity was investigated.The results indicate that the antioxidant capacity of BSA increased more than 10 times after binding Schiff-base metal complexes.     

Equilibrium Studies of Schiff Bases and Their Complexes with Ni(II), Cu(II) and Zn(II) derived from Salicylaldehyde and Some α-Amino Acids

The acid-base equilibria of Schiff bases derived from salicylaldehyde, glycine, alanine, serine, tyrosine, and phenylalanine, and their Ni(II), Cu(II) and Zn(II) complex formation equilibria were investigated by a potentiometric method in aqueous solution (t = 25^∘C, μ = 0.1 M, KCl). The data from the potentiometric titrations were evaluated by means of the BEST computer program. The order of the formation constant values of the Schiff bases was Sal-Ala > Sal-Gly > Sal-Ser > Sal-Phe > Sal-Tyr, which is the same order as the increasing log K₁ values of amino acids (and the log K₂ values of tyrosine) with the exception of an inversion between serine and phenylalanine. Also, it was seen that the stability constants, log β₁ and log β₂, of Schiff base–metal complexes vary for all the metal ions investigated, viz., Sal-Gly > Sal-Ala > Sal-Ser > Sal-Tyr > Sal-Phe with the exception of Sal-Gly in the copper complex. The effect of the nature of the amino acids on their formation, protonation and stability constants was also discussed.     

Detection of binuclear copper-caffeine complexes under electrospray ionization condition

A number of copper salts, Cu(OOCCH(3))(2), Cu(ClO(4))(2), Cu(NO(3))(2), CuCl(2) and CuSO(4) have been tested for their ability to form binuclear copper-caffeine complexes. The electrospray ionization (ESI) mass spectra of methanol solution containing caffeine and CuCl(2) or CuSO(4) show signals of two copper atom containing ions, so the signals correspond to binuclear complexes: [2Caf + Cu(2)SO(4)](+), [2Caf + Cu(2)](+), [2Caf + Cu(2)Cl](+), [2Caf + Cu(2)Cl(2)](+) and [2Caf + Cu(2)Cl(3)](+). Sulfate and chloride anion are characterized by charge densities higher than those of the carboxylate, nitrate and perchlorate anion. Thus, due to the electrostatic forces, the binuclear complexes containing SO(4)(2-) or Cl(-) can survive the transfer from solution to the gas phase and then can successfully be observed on ESI mass spectra. The ion [2Caf + Cu(2)Cl(3)](+) is present in solution and could be detected when using methanol/chloroform as solvent. The ions [2Caf + Cu(2)](+), [2Caf + Cu(2)Cl](+) and [2Caf + Cu(2)Cl(2)](+) are formed from the [2Caf + Cu(2)Cl(3)](+) ion (by subsequent loss of Cl atoms) on transfer from the solution to the gas phase or in the gas phase. The ion [2Caf + Cu(2)](+) does not contain a bridging agent, thus it is reasonable to assume that it contains a Cu-Cu bond.     

Syntheses, electronic structures, and EPR/UV-vis-NIR spectroelectrochemistry of nickel(II), copper(II), and zinc(II) complexes with a tetradentate ligand based on S-methylisothiosemicarbazide

Template condensation of 3,5-di-tert-butyl-2-hydroxybenzaldehyde S-methylisothiosemicarbazone with pentane-2,4-dione and triethyl orthoformate at elevated temperatures resulted in metal complexes of the type M(II)L, where M = Ni and Cu and H(2)L = a novel tetradentate ligand. These complexes are relevant to the active site of the copper enzymes galactose oxidase and glyoxal oxidase. Demetalation of Ni(II)L with gaseous hydrogen chloride in chloroform afforded the metal-free ligand H(2)L. Then by the reaction of H(2)L with Zn(CH(3)COO)(2)·2H(2)O in a 1:1 molar ratio in 1:2 chloroform/methanol, the complex Zn(II)L(CH(3)OH) was prepared. The three metal complexes and the prepared ligand were characterized by spectroscopic methods (IR, UV-vis, and NMR spectroscopy), X-ray crystallography, and DFT calculations. Electrochemically generated one-electron oxidized metal complexes [NiL](+), [CuL](+), and [ZnL(CH(3)OH)](+) and the metal-free ligand cation radical [H(2)L](+?) were studied by EPR/UV-vis-NIR and DFT calculations. These studies demonstrated the interaction between the metal ion and the phenoxyl radical.     

Transition metal complex cations as reagents for gas-phase transformation of multiply deprotonated polypeptides

Triply deprotonated DGAILDGAILD was reacted in the gas-phase with doubly charged copper, cobalt, and iron metal complexes containing either two or three phenanthroline ligands. Reaction products result from two major pathways. The first pathway involves the transfer of an electron from the negatively charged peptide to the transition-metal complex. The other major pathway consists of the displacement of the phenanthroline ligands by the peptide resulting in the incorporation of the transition-metal into the peptide to form [M − 3H + X^II]⁻ ions, where X is Cu, Co, or Fe, respectively. The extent to which each pathway contributes is dependent on the nature of transition-metal complex. In general, bis-phen complexes result in more electron-transfer than the tris—phen complexes, while the tris—phen complexes result in more metal insertion. The metal in the complex plays a large role as well, with the Cu containing complexes giving rise to more electron transfer than the corresponding complexes of Co and Fe. The results show that a single reagent solution can be used to achieve two distinct sets of products (i.e., electron-transfer products and metal insertion products). These results constitute the demonstration of novel means for the gas-phase transformation of peptide anions from one ion type to another via ion/ion reactions using reagents formed via electrospray ionization.     

A novel dinuclear Schiff-base copper(II) complex modified electrode for ascorbic acid catalytic oxidation and determination

A new dinuclear copper salicylaldehyde-glycine Schiff-base complex [Cu(2)(Sal-Gly)(2)(H(2)O)(2)] was synthesized and structurally characterized. [Cu(2)(Sal-Gly)(2)(H(2)O)(2)] crystallized in the monoclinic system in the P2(1)/c space group. The molecule is a dinuclear complex, formed by two [Cu(Sal-Gly)(H(2)O)] units. The electropolymerization properties of the copper complex on a glass carbon electrode were studied at different potential ranges. The electropolymerization occurred when the high scan potential reached 1.4 V. The modified electrode exhibited good electrocatalytic oxidation properties to ascorbic acid and showed a sensitivity of 22.9 nA μM(-1) (r(2) = 0.9998) and detection limit of 0.39 μM (S/N = 3) in the amperometric determination of ascorbic acid. The designed determination method can be used to analyze vitamin C tablets.     

Ternary complexes involving copper(II) and amino acids,peptides and DNA constituents. The kinetics of hydrolysis of α-amino acid esters

Binary and ternary complexes of copper(II) involving picolylamine (Pic) and amino acids, peptides (HL) or DNA constituents have been investigated. Ternary complexes of amino acids or peptides are formed by simultaneous reactions. Amino acids form the Cu(Pic)L complex, whereas peptides form Cu(Pic)L and Cu(Pic)(LH_–1). The ternary complexes of copper(II) with picolylamine and DNA are formed in a stepwise process, whereby binding of copper(II) to picolylamine is followed by ligation of the DNA components. The stability of the ternary complexes is compared with the stabilities of the corresponding binary complexes. The hydrolysis of glycine methyl ester (MeGly) is catalysed by the Cu(pic)²⁺ complex. The kinetic data is fitted assuming that the hydrolysis proceeds in two steps. The first step, involving coordination of the amino acid ester by the amino and carbonyl groups, is followed by rate-determining attack by the OH^– ion. The second step involves equilibrium formation of the hydroxo-complex, Cu(pic)(MeGly)(OH), followed by intramolecular attack.     

Dynamic study of metal-ion incorporation into porphyrins based on the dynamic characterization of metal ions and on sitting-atop complex formation.

We succeeded in the detection of the sitting-atop (SAT) copper(II) complex of TPP (5,10,15,20-tetraphenylporphyrin) in acetonitrile (AN) as a solvent with a very low Br?nsted basicity, where two pyrrolenine nitrogens in the Cu(II)-SAT complex coordinate to the metal ion and two protons still remain on the pyrrole nitrogens. The structure parameters around the copper(II) ion in the Cu(II)-SAT complex, as determined by a fluorescent EXAFS method, suggest an axially elongated and equatorially distorted six-coordinate geometry. We measured the rates of the formation reaction of the SAT complexes for a series of transition metal(II) ions in AN using the stopped-flow technique. We propose the mechanism where there is a rapid deformation equilibrium of the porphyrin ring prior to the rate-determining step of the bond rupture of a coordinated solvent molecule on the metal(II) ion. Furthermore, we measured the rates of the deprotonation reaction of the Cu(II)-SAT complex by some Br?nsted bases and indicated that the rate-determining step is the attack of the base on the proton of the pyrrole nitrogen in the SAT complex. Finally, a unified mechanism relevant to the porphyrin metalation mechanism has been proposed.     

Matrix-assisted laser desorption/ionization Fourier transform mass spectrometry of luteinizing hormone releasing hormone-metal ion complexes

Complexes of luteinizing hormone releasing hormone (LHRH) with divalent metal ions (Ni, Zn, Cu) have been studied by matrix-assisted laser desorption ionization (MALDI) and Fourier transform mass spectrometry. LHRH-metal complexes were detected in high abundance for all three metals from synthesized samples, particularly in negative ion mode. The mixture of the apopeptide with the metal salts yielded in most cases a very minor signal of metal-complex ions. As opposed to Ni and Zn, copper complex ions were mostly observed as Cu(I) adducts. This can be partly attributed to plume reactions of Cu(I) with the apopeptide. the Cu(II) complexes appeared only for the synthetic complex. We show how to distinguish between the contribution to the overall signal from desorbed complexes and from Cu(I) complexes formed in the MALDI plume.