壳寡糖锌(Ⅱ)配合物的合成与结构表征

以壳寡糖(COS)为配位体,锌(Ⅱ)离子为配位离子,在均相反应条件下合成了壳寡糖锌(Ⅱ)配合物(COS-Zn),并优化了配合物的合成条件.利用红外光谱法(FT-IR)、差热分析法(DTA)和元素分析(EA)进行结构表征,并对配位机理进行了初步探讨.     

壳聚糖和壳寡糖的磷酸化研究

以甲磺酸为溶剂,壳聚糖(CTS)和壳寡糖(COS)为原料,分别与五氧化二磷反应合成其磷酸酯。用电位滴定法测定取代度(DS),并用红外光谱法(FT-IR)和差热分析法(DTA)进行结构表征。通过分析壳聚糖与壳寡糖磷酸化正交实验结果,得出了甲磺酸用量、五氧化二磷用量、温度和反应时间等因素对产物取代度的影响,优化了合成工艺,并通过结构分析对两者进行了比较。     

血清白蛋白的铜(Ⅱ)-乙酰丙酮络合吸附波法测定

在pH6．8的磷酸盐缓冲溶液中,血清白蛋白与铜(Ⅱ)-乙酰丙酮络合物反应作用生成一种在汞电极上吸附性很弱的铜(Ⅱ)-血清白蛋白惰性络合物,使铜(Ⅱ)-乙酰丙酮络合物在-0．28V(vs．SCE)络合吸附波还原峰电流降低,电流降低值与1～30mg/L范围内牛血清白蛋白(BSA)或1～32mg/L范围内人血清白蛋白(HSA)呈线性关系;检出限分别为0．5和0．6mg/L。运用该法测定了人血清样品中蛋白质含量,结果满意。     

含酚氧桥的新型Cu(Ⅱ)-Mn(Ⅱ)和Cu(Ⅱ)-Co(Ⅱ)配合物的合成和磁性

合成了3种新型配合物[Cu(samen)Mn(NO_(2-)Phen)_2](1)、[Cu(sampn)Mn(NO_(2-)Phen)_2](2)和[Cu(samen)CO(terp)](3)(samen~(4-)、sampn~(4-)、NO_(2-)Phen和terp分别表示N,N′-乙二水杨酰胺根阴离子、N,N′-1,2-丙二水杨酰胺根阴离子、5-硝基-1,10-菲绕啉和联三吡啶),测得配合物的变温磁化率,求出交换积分,J分别为-63cm~(-1)(1)、—65cm~(-1)(2)和—7.68cm~(-1)(3),表明金属离子间有反铁磁超交换作用。     

三联吡啶羧基Zn(Ⅱ)，Cu(Ⅱ)和Fe(Ⅱ)配合物研究

本文通过溶剂热法合成了三个基于4’-羧基-2,2’∶6’,2"-三联吡啶(HL)的单核配合物,其分子式为[ML₂]·4H₂O(1,M=Zn(Ⅱ);2,M=Cu(Ⅱ);3,M=Fe(Ⅱ)),并分别对其进行了元素分析、波谱、单晶和粉末衍射表征。晶体结构测试结果表明3个配合物为异质同晶结构,都属于四方晶系的I42d空间群。配合物1~3都是1个二价金属离子和2个羧基未配位且去质子化的三齿螯合配体L配位形成的单核结构,通过分子间π-π堆积和氢键作用拓展成三维超分子网络结构。由于二价Zn离子的全充满d¹⁰电子构型,配合物1与其配体相比具有明显的室温固态蓝色荧光发射性质。     

三联吡啶羧基Zn(Ⅱ),Cu(Ⅱ)和Fe(Ⅱ)配合物研究

本文通过溶剂热法合成了三个基于4'-羧基-2,2':6',2"-三联吡啶(HL)的单核配合物,其分子式为[ML₂]·4H₂O(1,M=Zn(Ⅱ);2,M=Cu(Ⅱ);3,M=Fe(Ⅱ)),并分别对其进行了元素分析、波谱、单晶和粉末衍射表征。晶体结构测试结果表明3个配合物为异质同晶结构,都属于四方晶系的I42d空间群。配合物1~3都是1个二价金属离子和2个羧基未配位且去质子化的三齿螯合配体L配位形成的单核结构,通过分子间π-π堆积和氢键作用拓展成三维超分子网络结构。由于二价Zn离子的全充满d₁₀配位构型,配合物1与其配体相比具有明显的室温固态蓝色荧光发射性质。     

酚氧桥联的不对称双铜(Ⅱ)和铜(Ⅱ)-锌(Ⅱ)配合物的合成和磁性

本文合成了一组新的不对称双核配合物「Cu(samen)Cu(terp)」和「Cu(samen)Zn(terp)」,samen~4和terp分别表示N N’-乙二水杨酰胺胺根阴离子和2.2′:6′2″-联三吡啶。配合物「Cu(samen)Cu(terp)」的变温磁化率已测,其数值用最小二乘法与Bleancy-Bowers方程拟合,求得交换积分J=-0.538cm~(-1),表明配合物中铜离子间有极弱的反铁磁自旋交换作用。     

8-氮鸟嘌呤与铜(Ⅱ)的络合吸附波

用单扫描极谱法研究了8-氮鸟嘌呤(8-AG)与Cu2+形成络合物的条件,测定了该络合物有关的特征常数。在pH 3.00的HAc-NH4Ac缓冲溶液中,8-AG与Cu2+可以形成1∶1的络合物。该络合物产生一个不可逆吸附还原波,有1个电子和1个质子参与了电极反应,该络合物的条件稳定常数为5.73×105,反应活化能为12.1 kJ/mol,电极反应速率常数为1.04×10-4cm/s。     

Cu(Ⅱ)-DApCM-V(Ⅴ) 体系阻抑光度法测定微量铜

在磷酸介质中,Ｃｕ（Ⅱ）能抑制二安替比林对氯苯基甲烷（ＤＡｐＣＭ）与钒（Ⅴ）的显色反应。研究了反应条件和动力学参数,建立了测定微量铜（Ⅱ）的新方法。其线性范围质量浓度为０．０４－０．１８ｍｇ／Ｌ,检出限为０．０４ｍｇ／Ｌ,用于粗铅和铝合金样品中铜的测定,结果满意。     

含草酰胺桥的Cu(Ⅱ)-Fe(Ⅱ)和Cu(Ⅱ)-Zn(Ⅱ)双核配合物的合成、磁性及生物活性

抗菌活性;含草酰胺桥的Cu(Ⅱ)-Fe(Ⅱ)和Cu(Ⅱ)-Zn(Ⅱ)双核配合物的合成、磁性及生物活性     

Complexation of copper(II) with 2-dimethylaminomethylphenol

Conclusions With Cu²⁺ 2-dimethylaminomethylphenol forms a complex with a 11 composition, in which a neutral form of the liquid participates. A stability constant of the complex in the 40% aqueous-ethanol solution has been determined.Translated from Izvestiya Akademii Nauk SSSR, Seriya Khimicheskaya, No. 7, pp. 1641–1643, July, 1985.     

Complexation and determination of palladium (II) ion with para-Cl-phenylazo-R-acid spectrophotometrically

The complexation of para-Cl-phenylazo-R-acid azo dye with Pd(II) has been studied spectrophotometrically. Protonation constant (pK(a)) of the ligand has been calculated and the stability conditional constants of para-Cl-phenylazo-R-acid ligand with palladium ion has been determined at a constant temperature (25.0 degrees C), where the molar ratio of this complex is 1:1 (metal:ligand) with logbeta(1)=3.75, and 1:2 with logbeta(2)=8.55. Solid complex of para-Cl-phenylazo-R-acid has been prepared and characterized on the basis of elemental analysis and FTIR spectral data. A procedure for the spectrophotometric determination of Pd(II) using para-Cl-phenylazo-R-acid as a new azo chromophore is proposed where it is rapid, sensitive and highly specific. Beer's law was obeyed in the range 0.50-10.00 ppm at pH 5.0-6.0 to form a violet-red complex (epsilon=7.7 x 10(4) l(-1) mol(-1) cm(-1) at lambda(max)=560 nm). Metal ions such as Cu(II), Cr(III), La(III), Yb(III), Y(III), and Rh(III) interfere with the complex. Ammonium salt of trimellitic acid is used to precipitate some of the interfering ions and a scheme for separation of Pd(II) from a synthetic mixture similar in composition to platinum ore or deposit was made.     

Complexation of copper(II) with azo derivatives of benzoylacetone

1-Phenyl-2-[2-hydroxy-3-sulfo-5-nitrophenylazo]butadione-1,3 (H₂L) was synthesized from benzoylacetone. The dissociation constants of the reagent were determined (pK ₁ = 4.98 ± 0.03 and pK ₂ = 8.53 ± 0.01). Stability constants of some metal complexes with this reagent were determined by potentiometric and conductometric titrations. The stability of these complexes decreased in the following order: Fe > Cu > UO₂ > Ni > Co > Zn > Cd > Mn > Mg > Ca. The copper(II) H₂L complex with a stoichiometry of 1: 2 was studied by photometry. ε = 1.4 × 10⁴, Beer is law was obeyed in the copper concentration range from 0.25 to 3.07 μg/mL. The effect of foreign ions and masking agents on complexation was studied. A procedure for the photometric determination of copper(II) in seawater was developed.     

Complexation of copper ions with histidine-containing tripeptides immobilized on solid surfaces

Short oligopeptides that complex with metal ions with high affinity and high specificity are of interest to the design of chemical sensors. In this study, we compare the complexation properties of two copper-selective tripeptides, Gly-Gly-His and His-Gly-Gly, either in aqueous solutions or immobilized on solid surfaces. Our results show that the copper complex formed by Gly-Gly-His is more stable than the complex formed by His-Gly-Gly in aqueous solutions, because the position of histidine (His) in the Gly-Gly-His permits the formation of a tetragonal copper complex with a high stability. However, when the tripeptides are immobilized on aldehyde-decorated silicon wafer surfaces under a reaction condition that gives rise to near maximum surface densities of tripeptides, both immobilized Gly-Gly-His and His-Gly-Gly experience strong steric hindrance on the over-crowded surfaces. The surface crowding effect causes less complexation with copper ions than that in aqueous solutions. To ensure a proper surface density on the surface for complexation with copper ions, a so-called two-dimensional (2D) metal-ion imprinting technique is employed to avoid the surface crowdedness. By immobilizing Gly-Gly-His in the presence of copper ions, we create a tripeptide-functionalized surface that exhibits high complexation capability for copper ions. We attribute the higher copper complexation capability to the proper intermolecular distances obtained from the ion-imprinting procedure that gives the copper-tripeptide complex a preferential tetragonal geometry. Our results show that the amounts of copper complexed to a copper-imprinted surface functionalized with Gly-Gly-His are 62% higher than those of a nonimprinted surface.     

Complexation of copper(II)-montmorillonite with a modified cyclodextrin

The uptake reaction of Cu(II)-montmorillonite with mono-(6--aminoethylamino-6-deoxy)--cyclodextrin (CDen) has been examined at 25°C. The CDen molecules in their neutral or cationic forms are taken up by forming complexes with the interlayer Cu(II) ions (Cu_int) and by displacing protons at the clay surface. At low uptakes of CDen, 11 complexes of CDen with Cu_int are intercalated as a monolayer of 13.7 Å in thickness, with their opening faces parallel to the interlayer surface. At higher contents, the CDen-Cu_int complexes are more voluminously packed to form two intercalated phases with larger spacings until a bilayer of 23.9 Å in thickness is formed. The uptake by the mode of ion exchange proceeds increasingly at the intermediate uptake stage. At higher levels, however, this additional uptake is decreased rapidly due to the increase in the pH of solution, resulting in a maximum in the curve of CDen uptake against CDen added.     

Complexation of poly(acrylic acid)s with uranyl ion

The complexation of uranyl ion (UO₂²⁺) in aqueous solution with polymers containing carboxylic acid groups was studied potentiometrically. Overall formation constants of the uranyl complexes with poly(methacrylic acid) and crosslinked poly(acrylic acid) were much larger than those with the corresponding low molecular carboxylic acids. Decrease in the viscosity of the polymer solution on adding uranyl ion indicated that poly(acrylic acid) forms intra-polymer chelates with uranyl ion. The crosslinked poly(acrylic acid) adsorbed uranyl ions at higher efficiency than transition metal ions.     

Metal ion interaction with phosphorylated tyrosine analogue monolayers on gold

Phosphorylated tyrosine analogue molecules (pTyr-PT) were assembled onto gold substrates, and the resulting monolayers were used for metal ion interaction studies. The monolayers were characterized by X-ray photoelectron spectroscopy (XPS), infrared reflection-absorption spectroscopy (IRAS), cyclic voltammetry (CV), and electrochemical impedance spectroscopy (EIS), both prior to and after exposure to metal ions. XPS verified the elemental composition of the molecular adsorbate and the presence of metal ions coordinated to the phosphate groups. Both the angle-dependent XPS and IRAS results were consistent with the change in the structural orientation of the pTyr-PT monolayer upon exposure to metal ions. The differential capacitance of the monolayers upon coordination of the metal ions was evaluated using EIS. These metal ions were found to significantly change the capacitance of the pTyr-PT monolayers in contrast to the nonphosphorylated tyrosine analogue (TPT). CV results showed reduced electrochemical blocking capabilities of the phosphorylated analogue monolayer when exposed to metal ions, supporting the change in the structure of the monolayer observed by XPS and IRAS. The largest change in the structure and interfacial capacitance was observed for aluminum ions, compared to calcium, magnesium, and chromium ions. This type of monolayer shows an excellent capability to coordinate metal ions and has a high potential for use as sensing layers in biochip applications to monitor the presence of metal ions.     

Complexation of tetrandrine with calcium ion probed by various spectroscopic methods and molecular modeling

The formation of the complex between tetrandrine and the calcium ion, in solution, was studied using FTIR, UV-Vis, ¹H NMR, ¹³C NMR and electrospray mass spectroscopy spectroscopic methods and molecular modeling. The calcium salts used were: Ca(ClO₄)₂·4H₂O and Ca(Picrate)₂ in the solvents: acetonitrile (CH₃CN), deuterated acetonitrile (CD₃CN) and tetrahydrofurane (THF). The determined complex stability constant was: 20277±67 dm³ mol⁻¹ and corresponding free energy ΔG₀=−5.820±0.002 kcal mol⁻¹. The molecular simulation of the complex formation with the MM3 Augmented force field integrated in CAChe provided useful data about its energy. Combining the experimental results and molecular modeling we propose a model for the structure of tetrandrine-Ca complex with an eight coordinated geometry.