氮杂冠醚及其Cu(Ⅱ)、Ni(Ⅱ)、Cd(Ⅱ)、Ag(Ⅰ)配合物的合成及性质研究

用直接合成法合成了一种新配体-1,7-N,N′-二(邻氨基苯基)-1,7-二氮杂-4,10-二氧杂环十二烷[L]。经元素分析¹H、¹³C核磁共振、质谱、红外光谱等分析证实了其结构。并藉该配体合成了Cu(Ⅱ),Cd(Ⅱ),Ag(Ⅰ),Ni(Ⅱ)四种固体配合物。经元素分析配合物的组成分别为:[CuCl₂]₂·L,[CdCl₂]₃·2L·2H₂O,[AgNO₃]₂·L,[NiCl₂]₂·L·H₂O.对配合物进行了红外光谱、紫外光谱、摩尔电导和差热分析。配合物的红外特征吸收峰均有明显位移或分裂;紫外特征吸收峰稍有位移。但摩尔吸光系数改变很大;摩尔电导表明配合物为1:1或接近2:1型电解质;差热分析表明配合物的热稳定性顺序为:Cd(Ⅱ)、Ni(Ⅱ)>Cu(Ⅱ)>Ag(Ⅰ)。对Cu(Ⅱ)配合物进行了ESR谱分析,并且对甲醇溶液中Cu(Ⅱ)与配体(L)的掺入反应动力学进行了初步研究,结果表明,掺入反应为典型的二级反应。     

NTO镉(Ⅱ)配合物的合成、结构及量子化学研究

通过3-硝基-1,2,4-三唑-5-酮(NTO)与碳酸镉反应, 合成了标题配合物[Cd(NTO)₄Cd(H₂O)6]·4H₂O. 其结构用单晶分析法测定. 所得晶体学参数为a = 2.1229(3), b = 0.6261(8), c = 2.1165(3) nm, β = 90.602(3)°, V = 2.977(6) nm³, Z = 4, D_c = 2.055 g·cm^-3, μ = 15.45 cm^-1, F(000) = 1824; 晶体属单斜晶系, 空间群为C2/c, 由2523个F₀ > 4σ(F₀)的可观察衍射点用于结构解析和修正, 数据经吸收修正, 并经Lp因子校正. 最终偏离因子R = 0.0282, wR = 0.0792. 晶体测定结果表明, 在一个晶胞中存在两种类型的配位金属镉原子, 它们分别与4个NTO负离子和6个水分子配位, 形成以Cd原子为中心的四面体和四方双锥结构的双核配合物. 根据实验构型运用SCF-PM3-MO方法计算了3-硝基-1,2,4-三唑-5-酮(NTO)的镉配合物的电子结构, 计算结果表明, 当[Cd(NTO)₄Cd(H₂O)₆]·4H₂O加热至分解时, 最先失去吸附水, 其次是配位水, 当加热至NTO^-分解时, 硝基首先失去. 从定域分子轨道能级和组成可知, 2个Cd²⁺都主要以5S AO轨道进行配位成键.     

金属—血清白蛋白的结构研究——Ⅵ.等离子点附近HSA和BSA中Cu(Ⅱ)和Ni(Ⅱ)金属中心的结构

本文用紫外光谱研究了等离子点附近HSA或BSA ¹Cu(Ⅱ)或Ni(Ⅱ)金属中心的结构。结果表明:在pH₄.0～5.3时,Cu(Ⅱ)—HSA配合物在低浓度时独具五配位的四方锥构型,高浓度时(>10^-4mol·l^-1)为四配位的四方平面构型,Cu(Ⅱ)—BSA、Ni(Ⅱ)—BSA在上述pH范围内均只存在四方平面构型。Cu(Ⅱ)、Ni(Ⅱ)结合位置与生理pH下的相同,均在白蛋白的N端三肽段上,与Asp^{1相似文献}   

核磁共振法(NMR)和pH法研究Zn(Ⅱ)与HEDP(1-羟基乙叉-1,1-二膦酸)的配合物

本文用核磁共振法(NMR)和pH法对Zn(Ⅱ)与1-羟基乙叉-1,1-二膦酸(1-hydroxyethylidenel,1-diphosphonic acid,简称HEDP,以H₄L表示)的配合物进行了研究,由于pH<7时溶液中有沉淀生成,故NMR的研究是在溶液pH>7时进行.测定了溶液中不同Zn(Ⅱ)/HEDP摩尔比和pH值时³¹PNMR的化学位移。研究结果表明在pH7.5-11.0范围内生成Zn(Ⅱ)/HEDP=1(摩尔比)组成的配合物,在pH11.8-12.3范围内生成Zn(Ⅱ)/HEDP=2(摩尔比)组成的配合物,分别用pH法和NMR法测定了上述组成配合物的稳定常数.结果如下: logK_[zn(HL)^-] logK_[znL^2-] logK_[zn2L] pH法 4.69 7.51 11.63 NMR法——6.88-7.19 12.44.     

Ni(Ⅱ)与HSA或BSA的结合平衡研究

用平衡透析法研究了生理pH(7.43)及pH(5.0)条件下Ni(Ⅱ)与HSA或BSA的结合平衡。Scatchard图分析表明 ,生理pH条件下 ,Ni(Ⅱ)在HSA或BSA中均有2个强结合部位 ,而在pH(5.0)条件下 ,只有1个强结合部位。Hill图分析表明Ni(Ⅱ)与HSA或BSA的结合均产生较强的正协同效应。通过不同pH对Ni(Ⅱ)与HSA或BSA结合的影响及Ni(Ⅱ)与Cu(Ⅱ)和Ca(Ⅱ)的竞争结合的结果 ,推测了两个强结合部位可能的结合位点和配位原子。竞争结果还表明Cu(Ⅱ)对Ni(Ⅱ)的结合有明显拮抗作用。Ca(Ⅱ)对Ni(Ⅱ)的结合影响很小。     

叠氮二(2,2''-联吡啶)钌(Ⅱ)配合物的光物理和光化学性质

本文研究了叠氮二(2,2'—联吡啶)钌(Ⅱ)配合物在有机溶剂及乙腈—水中的一些光物理和光化学性质。在77K的甲醇—乙醇玻璃态时,用245nm等波长激发表现较强的荧光,其最大发射峰在540nm,另一弱带在580nm。在室温甲醇中测得的磷光发射是弱的,且寿命<15us。 在254nm、300nm及514nm照射下,光反应机制及量子产率与溶剂、照射波长有关。在乙腈—水及乙腈中,分别用254nm和514nm照射均发生取代反应,最后的光产物为Ru(bpy)₂(N₃)(CH₃CN)⁺,配合物消失的量子产率分别为0.129±0.008mol einstein^-1及(6.77±0.22)×10^-5mol einstein^-1;在乙腈—水中用514nm照射,生成的光产物先是Ru(bpy)₂(N₃)(CH₃CN)⁺,再生成Ru(bpy)₂(CH₃CN)₂²⁺,配合物消失的量子产率为(5.32±0.13)×10^-4mol einstein^-1。     

La(Ⅲ)与HSA或BSA的结合平衡研究

用平衡透析法详细研究了pH=6.3条件下La(Ⅲ)与HSA或BSA的结合平衡.Scatchard图分析表明,La(Ⅲ)在HSA中有2个强结合部位和8个弱结合部位;在BSA中有2个强结合部位和6个弱结合部位.从La(Ⅲ)与Cu(Ⅱ),Zn(Ⅱ)和Cd(Ⅱ)等的竞争结合HSA或BSA的结果推测:La(Ⅲ)在HSA或BSA中的一个强结合部位的配位原子可能全部是氧原子.通过非线性最小二乘法拟合Bjerrum方程,首次报道了La(Ⅲ)-HSA和La(Ⅲ)-BSA体系的逐级稳定常数值,其K₁的数量级为10⁴.Hill系数及自由能偶合分析表明La(Ⅲ)与HSA或BSA的结合均产生一定的负协同效应.     

香草醛异烟酰腙与钴、镍、铜、锌和镉配合物的合成和性质研究

本文合成了香草醛异烟酰腙(H₂L^Ⅰ)和邻香草醛异烟酰腙(H₂L^Ⅱ)与钴(Ⅱ)、镍(Ⅱ)、铜(Ⅱ)、锌(Ⅱ)和镉(Ⅱ)的九个新配合物:M(HL^Ⅰ)₂·nH₂O[M(Ⅱ)=Co、Ni、Cu、Zn和Cd,n=0,2]和M(HL^Ⅱ)₂·nH₂O[M(Ⅱ)=Co、Ni、Cu和Zn,n=0-3]。采用     

N,N′-乙二水杨酰胺合镍(Ⅱ)酸根的双核镍(Ⅱ)及镍(Ⅱ)-铜(Ⅱ)配合物的合成及性能研究

以N,N′-乙二水杨酰胺合镍酸钠同二价金属离子和2,2-联吡啶(bpy)或1,10菲绕啉(phen)反应制得双核配合物,[Ni(samen)Cu(L)]和[Ni(samen)Ni(L)₂](L=bpy,phen).经元素分析。红外、电子光谱等方法已推定[Ni(samen)]^2-中的Ni(Ⅱ)的配位环境为平面四方型,而被bpy或phen配位的Cu(Ⅱ)和Ni(Ⅱ),分别为平面四方型和畸变八面体构型。 据此,本文指派了配合物的电子光谱,评价了Dq,B,β等配位场参数,并且用配位场理论模型算出了有效磁矩,Ni(Ⅱ)-Cu(Ⅱ)配合物的g₁₁,与g₁,结果理论值与实验值相当吻合。     

ATMP(氨基三甲叉膦酸)及其顺磁性Co(Ⅱ)配合物的核磁共振研究

本文用¹H、³¹P和¹³C核磁共振谱研究了ATMP(氨基三甲叉膦酸,以简式H₆L表示)及其顺磁性Co(Ⅱ)配合物。测定了不同C_co/C_ATMP摩尔比在不同pH值下的各向同性位移。定性地讨论顺磁性Co(Ⅱ)配合物在不同pH条件下的组成、电荷和空间构型变化对化学位移的影响。运用快速交换反应中化学位移与配合物浓度的关系,确定不同pH下的条件稳定常数。     

Cd（Ⅱ）与HSA或BSA的结合平衡研究

用平衡透析法详细研究了生理pH(7.43)条件下Cd(Ⅱ)与HSA或BSA的结合平衡.通过非线性最小二乘法拟合Bjerrum方程,首次报道了Cd(Ⅱ)-HSA和Cd(Ⅱ)-BSA体系的逐级稳定常数值,其K_1～K_3的数量级均为10~4;Hill系数和自由能偶合定量分析表明Cd(Ⅱ)与HSA或BSA的结合均产生在类似体系中少见的强的正协同效应,且Cd(Ⅱ)与HSA结合产生的正协同效应大于BSA;Scatchard图分析表明,Cd(Ⅱ)在HSA和BSA中均有3个强结合部位.通过Cd(Ⅱ)与Cu(Ⅱ),Zn(Ⅱ)或Ca(Ⅱ)等竞争结合HSA或BSA的结果,进一步讨论了Cd(Ⅱ)在HSA或BSA中强结合部位的可能位置和(或)配体.     

Binding equilibrium study between Mn( Ⅱ ) and HSA or BSA

The binding of Mn( Ⅱ ) to human serum albumin (HSA) or bovine serum albumin (BSA) has been studied by equilibrium dialysis at physiological pH (7. 43). The Scatchard analysis indicates that there are 1.8 and 1.9 strong binding sites of Mn( Ⅱ ) in HSA and BSA, respectively. The successive stability constants which are reported for the first time are obtained by non-linear least-squares methods fitting Bjerrum formula. For both Mn( Ⅱ )-HSA and Mn( Ⅱ )-BSA systems, the order of magnitude of K1 was found to be 104. The analyses of Hill plots and free energy coupling show that the positive cooperative effect was found in both Mn( Ⅱ )-HSA and Mn( Ⅱ )-BSA systems . The results of Mn ( Ⅱ ) competing with Cu ( Ⅱ ) 、 Zn(Ⅱ)、Cd( Ⅱ) or Ca( Ⅱ ) to bind to HSA or BSA further support the conjecture that there are two strong binding sites of Mn( Ⅱ) in both HSA and BSA. One is most probably located at the tripeptide segment of N- terminal sequence of HSA and BSA molecules involving four groups composed of n     

Cd(II)与HSA或BSA的结合平衡研究

用平衡透析法详细研究了生理pH(7.43)条件下Cd(II)与HSA或BSA的结合平衡。通过非线性最小二乘法拟合Bjerrum方程,首次报道了Cd(II)-HSA和Cd(II)-BSA体系的逐级稳定常数值,其K~1-K~3的数量级均为10^4;Hill系数和自由能偶合定量分析表明Cd(II)与HSA或BSA的结合均产生在类似体系中少见的强的正协同效应,且Cd(II)与HSA结合产生的正协同效应大于BSA;Scatchard图分析表明,Cd(II)在HSA和BSA中均有3个强结合部位。通过Cd(II)与Cu(II),Zn(II)或Ca(II)等竞争结合HSA或BSA的结果,进一步讨论了Cd(II)在HSA或BSA中强结合部位的可能位置和(或)配体。     

Removal of cadmium(II) and zinc(II) metal ions from binary aqueous solution by rice husk ash

The present study reports the competitive adsorptive removal of cadmium (Cd(II)) and zinc (Zn(II)) ions from binary systems using rice husk ash (RHA), a waste obtained from the rice husk-fired furnaces, as an adsorbent. The initial pH (pH₀) affects significantly the capacity of RHA for adsorbing the metallic ions in the aqueous solution. The pH₀ ≈ 6.0 is found to be the optimum for the removal of Cd(II) and Zn(II) ions by RHA. The single ion equilibrium adsorption from the binary solution is better represented by the non-competitive Redlich–Peterson (R–P) and the Freundlich models than by Langmuir model in the initial metal concentration range of 10–100 mg/l. The adsorption of Zn(II) ion is more than that of Cd(II) ion, and this trend is in agreement with the single-component adsorption data. The equilibrium metal removal decreases with increasing concentrations of the other metal ion and the combined effect of Cd(II) and Zn(II) ions on RHA is generally found to be antagonistic. Non-modified Langmuir, modified Langmuir, extended-Langmuir, extended-Freundlich, Sheindorf–Rebuhn–Sheintuch (SRS), non-modified R–P and modified R–P adsorption models were tested to find the most appropriate competitive adsorption isotherm for the binary adsorption of Cd(II) and Zn(II) ions onto RHA by minimizing the Marquardt's percent standard deviation (MPSD) error function. The extended-Freundlich model satisfactorily represents the adsorption equilibrium data of Cd(II) and Zn(II) ions onto RHA.     

The ELECTRICAL INTERFACIAL LAYER at theTiO2 (ANATASE)/ELECTROLYTE INTERFACE - ADSORPTION of Zn(II) and Cd(II) IONS

Mechanism of adsorption of Zn(II) and Cd(II) ions at the TiO₂ (anatase)/electrolyte interface has been studied by different experimental techniques (potentiometric titration, microelectrophoresis and adsorption measurements of zinc and cadmium species). It was found that the point of zero charge (pzc) of anatase (pH =5.8) was shifted to the lower pH values with increasing concentrations of Zn(II) or Cd(Il) ions. The surface charge of anatase in the presence of Zn(II) and Cd(II) for pH > pH_pzc was higher than that observed for original sample in NaClO₄ solutions only. Due to low coverage of anatase surface with Zn(II) or Cd(II) species almost no shift of the isoelectric point (iep) or charge reversal were observed. Adsorption density vs. pH plots for both Zn(Il) or Cd(II) showed, typical for multivalent ions, presence of “adsorption edge.”     

锌离子对缓冲液中槲皮素和牛血清白蛋白相互作用的影响

采用荧光光谱法和紫外光谱法研究了Zn2+离子对槲皮素(Qct)和牛血清白蛋白(BSA)在pH=7.4的Tris-HCl缓冲溶液中相互作用的影响;根据荧光猝灭双倒数图计算了Qct和BSA之间的结合常数和结合位点数.结果表明,Qct和Zn2+离子都可以使BSA的荧光强度发生猝灭;Qct和BSA之间的结合常数为3.17×107L.mol-1.s-1,结合位点数为1.32.定量计算表明,加入Zn2+离子后,Qct与BSA间的结合常数显著降低、结合位点数减小,表明Zn2+离子参与了Qct与BSA的结合过程.     

Monitoring of Zn(II) and Cd(II) adsorption on activated carbon from aqueous multicomponent solutions by differential pulse polarography (DPP)

The adsorption process of Zn(II) and Cd(II) from aqueous solution has been investigated from both kinetic and equilibrium standpoints, using differential pulse polarography (DPP) on a mercury dropping electrode as the analytical technique. With such an aim, adsorption experiments were performed using not only a single metal ion–Zn(II) or Cd(II) solution but also a multi-component ion metal–Zn(II), Cd(II) and Hg(II) solution. The influence of the pH change in the multi-component ion metal solution on the adsorption of Zn(II) and Cd(II) was also studied. The adsorption processes is relatively fast for Zn(II) and Cd(II). The presence of two foreign ions in the solution slightly speeds up the adsorption process for Zn(II) and significantly slows it down for Cd(II). The adsorption isotherms are similarly shaped for Zn(II) and Cd(II). The addition of the foreign ions has a more unfavourable effect on the adsorption for Cd(II) than for Zn(II). At pH 2, neither Zn(II) nor Cd(II) is adsorbed practically on the carbon. The voltammetric approach has proved to be a fast and efficient method that, at the same time, enables one to monitor the adsorption of Zn(II) and Cd(II) with potential on-line application, which could be useful in waste-water treatment.     

Preparation,Properties and Thermal Decompositions of Co(II), Ni(II), Cu(II), Zn(II) and Cd(II) Complexes of 2,5-dichlorobenzoic Acid

Co(II), Ni(II), Cu(II), Zn(II) and Cd(II) 2,5-dichlorobenzoates were prepared and their compositions and solubilities in water at 295 K were determined. The IR spectra and X-ray diffractograms of the obtained complexes were recorded. The complexes of Co(II), Ni(II), Cu(II), Zn(II) and Cd(II) were obtained as solids with a 1:2 molar ratio of metal to organic ligand and different degrees of hydration. When heated at a heating rate of 10 K min^-1, the hydrated complexes lose some (Co, Zn) or all (Ni, Cu, Cd) of the crystallization water molecules and then decompose to oxide MO (Co, Ni) or gaseous products (Cu, Zn, Cd). When heated at a heating rate of 5 K min^-1, the complexes of Ni(II) and Cu(II) lose some (Ni) or all (Cu) of the crystallization water molecules and then decompose directly to MO. This revised version was published online in July 2006 with corrections to the Cover Date.     

Multinuclear Magnetic Resonance Study of Zinc(II) and Cadmium(II) Complexing with Isothiocyanate

A study of zinc(II) and cadmium(II) complexes with isothiocyanate ion has been completed, using a low-temperature, multinuclear magnetic resonance technique that permits the observation of separate resonance signals for bound and free ligand, and Cd(II) metal ion. The Zn²⁺–NCS^– complexes were studied by ¹H, ¹³C, and ¹⁵N NMR spectroscopy. In the ¹H spectra, the intensity of the coordinated water signal, corresponding to a Zn(II) hydration number of six in the absence of NCS^–, decreases dramatically as this anion is added, indicating the complexing process involves more than a simple 1:1 ligand replacement. The ¹³C and ¹⁵N NMR spectra reveal signals for four species, most reasonably assigned to a series of tetrahedrally coordinated Zn²⁺–NCS^– complexes. In the Cd²⁺–NCS^– solution spectra, the ¹³C and ¹⁵N signals for four complexes also are observed and they are three line patterns, corresponding to a doublet from ¹¹³Cd J-coupling, and a dominant central peak, resulting from bonding to magnetically inactive Cd isotopes. The ¹¹³Cd spectra, showing signals for four complexes, correlate well in all respects with the ¹³C and ¹⁵N results, including coupling in specific cases. The spectral results for both metal ions reflect binding at the nitrogen atom of NCS^–, with the complexes changing from an octahedral to a tetrahedral configuration when doing so. Confirming evidence for these conclusions also was provided by several infrared measurements of these metal–ion systems.     

Synthesis and application of a novel magnetic nanosorbent for determination of trace Cd(II), Ni(II), Pb(II), and Zn(II) in environmental samples

In this work for the first time, Fe₃O₄@SiO₂ core–shell nanoparticles functionalized with isatin groups as a magnetic nanosorbent was applied for the simultaneous extraction of trace amounts of cadmium(II), nickel(II), lead(II), and zinc(II). The characterization of this nanosorbent was studied using Fourier transform infrared spectroscopy, scanning electron microscopy, energy-dispersive X-ray spectrometry, X-ray diffraction, vibrating sample magnetometer and thermogravimetric analysis. The effect of several factors such as pH, amount of sorbent, extraction time, type and volume of the eluent, sample volume, sorption capacity, and potentially interfering ions was investigated. In the selected conditions, it was observed that the limits of detection were 0.11 ng mL^?1 for Cd(II), 0.28 ng mL^?1 for Ni(II), 0.47 ng mL^?1 for Pb(II), and 0.21 ng mL^?1 for Zn(II), and the maximum sorption capacity of this suggested magnetic nanosorbent was 120, 112, 100, and 100 mg g^?1 for Cd(II), Ni(II), Pb(II), and Zn(II), respectively. Also, the precision of the method (RSD%) for ten replicate measurements was found 2.5, 2.5, 2.8, and 3.1%, for Cd(II), Ni(II), Pb(II), and Zn(II) ions, respectively. Finally, the suggested procedure was applied for determination of cadmium(II), nickel(II), lead(II), and zinc(II) at trace levels in different water and agricultural products with satisfactory results.