含茂、非茂混合配体钛族络合物的合成与催化烯烃聚合的研究进展

目前金属有机钛族络合物的发展呈现出多元化的趋势:茂络合物、非茂络合物以及茂非茂混合配体络合物,而其中茂、非茂混合配体络合物是近年来发展的一个新亮点.关于茂钛族络合物、非茂钛族络合物近年已经有过许多的综述,而关于茂、非茂混合配体钛族络合物的综述却很少.综述了近年来茂、非茂混合配体钛族络合物合成与催化烯烃聚合的研究进展.     

多元络合物显色反应的研究——Ⅰ.稀土-铬天青S-1, 10-邻菲啰啉-溴化十六烷基三甲铵体系

近年来在分析化学中广泛使用多元络合物,它的优越性在于提高了反应的灵敏度和选择性.在三元络合物中,一般说来,混合配位体络合物(混配络合物)的选择性较好,而胶束增溶络合物(胶溶络合物)的灵敏度较高,这在稀土多元络合物的显色反应中也表现得很明显.为了提高多元络合物显色反应的灵敏度和改善选择性,我们设想把混配络合物和胶溶络合物统一在一个多元络合物体系中.胶溶络合物中以三苯甲烷染料研究最多,其中应用较广的是铬天青S和铬菁R,因此,我们对稀土-铬天青S-1,10-邻菲啰啉-溴化十六烷基三甲铵四元络合物的显色反应进行系统的研究.     

过渡金属络离子的解离动力学研究

利用分光光度法研究过渡金属络合物的稳定性即络合物解离及缔合反应动力学,始终是络合物化学的研究课题之一。六十年代的研究成果表明,某一特定金属和不同配位体形成的络合物,其络合物生成     

三元络合物在分析化学中的应用

一、引言三元络合物系指由三个组分所形成的单核或多核的混合配位络合物。通常由一个中心离子和两个配位体或两种金属和一个配位体所形成。所以更恰当些,应称为混合型络合物或异配位络合物。三元络合物在络合物化学中是一个新的领域。近年来在分析化学,特别是在分光光度法中的应用,得到迅速的发展,这主要由于: 1.应用三元络合物的方法一般具有较高的灵敏度:例如,在金属的有色络合物中加入鎓碱,灵敏度往往可提高几倍,这是目前提高显色     

高分子金属络合物的性能及应用进展

介绍了高分子金属络合物的种类及合成。综述了高分子金属络合物不同于低分子络合物的催化性能、电学性能、光学性能和磁性 ,以及高分子金属络合物作为催化剂、光学材料、电学材料等方面的应用进展。     

锰-铬天青S-邻菲罗啉-溴化十六烷基三甲铵体系的多元络合物的分光光度法研究

多元络合物是络合物化学中一个新兴领域,由于多元络合物具有不少优异性能,在分析化学上早已引起人们的重视。近些年来,我国分析工作者应用混合型配位络合物与阳离子表面活性剂反应形成多元络合物来测定稀土元素已获得成功。锰-铬天青S-邻菲罗啉-溴化十六烷基三甲铵体系的多元络合物的分光光度法的研究似未见报导。本文系统地研究了该多元络合物的最佳形成条件,试验了大多数常见离子的干扰情况,测定了络合物的组成及摩尔吸光系数,并用建立的方法于钢铁和铝合金中锰的测定获得较满意的结果。     

光密度法研究溶液中的络合物

在分析化学中愈来愈广泛的应用着络合物生成反应,故络合物的研究对分析化学具有重大的意义。然而过去对溶液中络合物的研究是不够的,在应用络合物生成反应时,对于溶液中络合物的组成一般不去研究,而从固体盐类的组成来推测,因此常常导出不正确的结论。例如,比色测定铁最常用的硫氰酸铁络合物过去却很少研究,而推测为 Fe(CNS)_3,[Fe(CNS)_6](?)等,但是经过 Bent 等特别是等的详细研究证明溶液中生成了许多配位数不同的络合物,而主要有色络合物的组成为     

氯化—甘氨酸六水合稀土固体络合物的合成及红外光谱研究

本文用稀土氯化和的与甘氨酸反应制备了标题络合物，测定了络合物的红外光谱，对其主要吸收带进行了归属，红外光谱的研究结果表明，甘氨酸以内盐的形式存在于络合物中的，通过羟基与稀土离子配位。水分子也参与了配位。并推测，Ｎｄ的络合物为双核络合物，其它稀土络合物具有一维无限长链结构。     

苯甲酰水杨酸的制备及其与稀土络合物光致发光现象研究

合成了苯甲酰水杨酸,以之为第一配体,以邻菲罗啉（phen)为第二配体,合成了Eu^3 的三元络合物以及Tb^3 的二元络合物。红外光谱说明苯甲酰水杨酸与稀土离子形成了络合物;荧光光谱显示铕络合物具有很好的单色性,并探讨了加入PVK后络合物对称性的变化。     

铜—氨基酸络合物的紫外光谱性质及其应用—络合物组成及稳定常数的…

本文从研究铜（Ⅱ），９种有代表性的氨基酸及其络合物的紫外光谱性质着手，探讨了络合物的组成，用计算校正的方法获得了络合物的吸光度，并进一步测定了络合物的组成比及稳定常数。     

A new method for determining the composition and stability constant of complexes of the form ambn

A new method is reported for determining the composition of complexes of the form A_mB_n; it can be used to differentiate mono- and polynuclear complexes. The method is based on that of Holme and Langmyhr. Good results were obtained for several complexes.     

Selective detection of specific protein-ligand complexes by electrosonic spray-precursor ion scan tandem mass spectrometry

A novel mass spectrometric method for the selective detection of specific protein-ligand complexes is presented. The new method is based on electrosonic spray ionization of samples containing protein and ligand molecules, and mass spectrometric detection using the precursor ion scanning function on a triple quadrupole instrument. Mass-selected intact protein-ligand complex ions are subjected to fragmentation by means of collision-induced dissociation in the collision cell of the instrument, while the second mass analyzer is set to the m/z of protonated ligand ions or their alkali metal adducts. The method allows for the detection of only those ions which yield ions characteristic of the ligand molecules upon fragmentation. Since the scan range of first analyzer is set well above the m/z of the ligand ion, and the CID conditions are established to permit fragmentation of only loosely bound, noncovalent complexes, the method is specific to the detection of protein-ligand complexes under described conditions. Behavior of biologically specific and nonspecific complexes was compared under various instrumental settings. Parameters were optimized to obtain maximal selectivity for specific complexes. Specific and nonspecific complexes were found to show markedly different fragmentation characteristics, which can be a basis for selective detection of complexes with biological relevance. Preparation of specific and nonspecific complexes containing identical building blocks was attempted. Complex ions with identical stoichiometry but different origin showed the expected difference in fragmentation characteristics, which gives direct evidence for the different mechanism of specific versus nonspecific complex ion formation.     

Weighted edge based clustering to identify protein complexes in protein–protein interaction networks incorporating gene expression profile

Protein complex detection from protein–protein interaction (PPI) network has received a lot of focus in recent years. A number of methods identify protein complexes as dense sub-graphs using network information while several other methods detect protein complexes based on topological information. While the methods based on identifying dense sub-graphs are more effective in identifying protein complexes, not all protein complexes have high density. Moreover, existing methods focus more on static PPI networks and usually overlook the dynamic nature of protein complexes. Here, we propose a new method, Weighted Edge based Clustering (WEC), to identify protein complexes based on the weight of the edge between two interacting proteins, where the weight is defined by the edge clustering coefficient and the gene expression correlation between the interacting proteins. Our WEC method is capable of detecting highly inter-connected and co-expressed protein complexes. The experimental results of WEC on three real life data shows that our method can detect protein complexes effectively in comparison with other highly cited existing methods.Availability: The WEC tool is available at http://agnigarh.tezu.ernet.in/~rosy8/shared.html.     

2-乙酰吡啶吖嗪及其与Co2+、Ni2+、Fe3+、Zn2+配合物的合成和生物活性

过渡金属;超氧离子;白血病;肺癌;2-乙酰吡啶吖嗪及其与Co2+、Ni2+、Fe3+、Zn2+配合物的合成和生物活性     

A new graphical method for determining stability constants of weak and polynuclear complexes

A graphical method is proposed for differentiating mono- and poly-nuclear complexes as well as for determining the stability constants of weak complexes. The method is based on the effect of dilution on the degree of dissociation of the complex. The precision for log K is ±0.02 for a degree of dissociation between 30 and 70%. The greatest values for log K that can be determined are 4.3, 12.4, 7.5 and 10.7 for 1:1, 2:2, 2:1 and 3:1 ligand: metal complexes, respectively. If log K₁ ? 5.7, the method permits log K₂ to be determined if simultaneous complexes are formed.     

Macromolecular metal complexes with transition-metal ions: Structure of a polymer and efficiency of complexation

A quantitative method of estimating the efficiency of formation of macromolecular metal complexes of carboxyl-containing (co)polymers with transition-metal ions in dilute solutions was developed. This method is based on the luminescence quenching of luminescently labeled macromolecules by transition-metal ions. With the use of this method, the effect of the chemical (including isomeric) structure of carboxyl-containing (co)polymers and external conditions on the stability of macromolecular metal complexes based on copper, nickel, and silver ions was assessed. With consideration for the data obtained, a targeted variation in the functional characteristics of macromolecular metal complexes may be accomplished.     

氢键复合物自组装性质的研究

超分子复合物体系因近年来发展较快及应用范围广而颇具吸引力。作为形成超分子复合物的主要手段,氢键自组装对于高分子聚合材料以及生命科学等领域有着重要的意义。本文根据氢键的多重性及不同氢键的缔合方式对氢键复合物进行分类,并对氢键自组装复合物的性质和研究状况作了综述,同时介绍了本研究组在此方面的理论研究工作。     

Genome-wide predicting disease-related protein complexes by walking on the heterogeneous network based on data integration and laplacian normalization

BackgroundAssociating protein complexes to human inherited diseases is critical for better understanding of biological processes and functional mechanisms of the disease. Many protein complexes have been identified and functionally annotated by computational and purification methods so far, however, the particular roles they were playing in causing disease have not yet been well determined.ResultsIn this study, we present a novel method to identify associations between protein complexes and diseases. First, we construct a disease-protein heterogeneous network based on data integration and laplacian normalization. Second, we apply a random walk with restart on heterogeneous network (RWRH) algorithm on this network to quantify the strength of the association between proteins and the query disease. Third, we sum over the scores of member proteins to obtain a summary score for each candidate protein complex, and then rank all candidate protein complexes according to their scores. With a series of leave-one-out cross-validation experiments, we found that our method not only possesses high performance but also demonstrates robustness regarding the parameters and the network structure. We test our approach with breast cancer and select top 20 highly ranked protein complexes, 17 of the selected protein complexes are evidenced to be connected with breast cancer.ConclusionsOur proposed method is effective in identifying disease-related protein complexes based on data integration and laplacian normalization.     

Separation-based approach to study dissociation kinetics of noncovalent DNA-multiple protein complexes

Noncovalent binding of DNA with multiple proteins is pivotal to many regulatory cellular processes. Due to the lack of experimental approaches, the kinetics of assembly and disassembly of DNA-multiple proteins complexes have never been studied. Here, we report on a first method capable of measuring disassembly kinetics of such complexes. The method is based on continuous spatial separation of different complexes. The kinetics of multiple complex dissociation processes are also spatially separated, which in turn facilitates finding their rate constants. Our separation-based approach was compared with a conventional no-separation approach by using computer simulation of dissociation kinetics. It proved to be much more accurate than the no-separation approach and to be a powerful tool for testing hypothetical mechanisms of the disassembly of DNA-multiple proteins complexes. An experimental implementation of the separation-based approach was finally demonstrated by using capillary electrophoresis as a separation method. The interaction between an 80 nucleotide long single-stranded DNA and single-stranded DNA binding protein was studied. DNA-protein complexes with one and two proteins were observed, and rate constants of their dissociation were determined. We foresee that a separation approach will be also developed to study the kinetics of the formation of DNA-multiple protein complexes.     

Speciation of Charged Complexes by Donnan Dialysis

Abstract

The assignment of metal complexes to various regimes on the basis of their dissociation kinetics is one type of metal speciation study. The most common scheme, which involves column ion-exchange as a means of separating free metal ions and metals in the form of highly labile complexes from other forms of metals in the sample, is demonstrated to categorize incorrectly stable, charged complexes such as iron(II) and nickel(II) o-phenanthroline as labile. Donnan dialysis is an alternative ion-exchange method for metal speciation studies. Data are provided which demonstrate that the above complexes are correctly assigned by the Donnan dialysis method. The relative labilities of ethylenediamine and triethylenetetramine complexes of iron (II) and nickel (II) are also correctly determined by Donnan dialysis.