Oxovanadium(IV) complexes of non-steroidal anti-inflammatory drugs: Synthesis,spectroscopy, and antimicrobial activity

Oxovanadium(IV) complexes with four different non-steroidal anti-inflammatory drugs have been synthesized. These complexes were characterized by different analytical techniques such as CHN, IR, UV-Vis spectroscopy, and mass spectrometry. The IR data show the bidentate nature of the ligands and reveal hexacoordinate geometry in the solid state. The complexes were tested for their biological activity against six different bacterial strains and plant pathogens, and all complexes showed good biological activity with few exceptions The text was submitted by the authors in English.     

A comparative study on half-inhibitory concentration of Schiff base-metal complexes reacting with bacteria

The metabolic inhibition of the three series of SG, O-VG and 2,4-L totaling eleven kinds of Schiff base complexes and two kind of corresponding metal compounds on Aerobacter aerogenes and Staphylococcus sureus has been studied microcalorimetrically. The studies reveal how, with reaction of different complexes, the difference in the metabolic power–time curves of the two kinds of bacteria metabolism. According to the power-time curves, the multiplication rate constant, generation time and inhibitory ratio of bacterial growth have been calculated, characterizating quantitatively the inhibition of Schiff base-metal complexes on bacteria metabolism. The relationship between the bacterial growth rate constant k and Schiff base-metal complex concentration c is thereby established, and on the basis of the quantity of half-inhibitory C_1/2 of Schiff base-metal complexes, the relationship between the structure of Schiff base-metal complexes and its antibacterial activity has been further studied by comparing the half-inhibitory quantity. A discussion of the cases of Schiff base-metal complexes of the same ligand at different metal ions, and of the same ions but different ligand reacting with different bacteria, has also been made, respectively, in comparative depth. It is found that, as for different bacteria, the same complex has different antibiotic activities, reflecting the difference between different kinds of bacteria; the inhibition of the same kind of bacteria varies with different complexes, showing the difference in the structure of the complexes, and thus providing useful information for the synthetic designing and the reasonable clinical administration of medicine of Schiff base drugs.     

Temperature-dependent interconversion of phosphoramidite-Cu complexes detected by combined diffusion studies, 31P NMR, and low-temperature NMR spectroscopy

For copper-catalyzed enantioselective conjugate additions, knowledge about the precatalytic and catalytic complexes has not yet been sufficiently developed to understand the strong influence of different temperatures on these famous reactions. Therefore, NMR experiments with four Cu(I) salts and two phosphoramidite ligands have been performed to elucidate the temperature dependence and the low-temperature structures of these copper complexes. The existence of the precatalytic binuclear complex with a mixed trigonal/tetrahedral coordination on copper is for the first time proven with direct NMR spectroscopic methods. Below 200 K, intermolecular interactions between free ligands and [Cu2X2L3] complexes induce binuclear [Cu2X2L4] complexes similar to the crystal structures. By combining diffusion experiments and (31)P integrals at different temperatures, it is for the first time possible to follow the formation of stoichiometrically different complexes, even under experimental conditions in which the (31)P signals of the complexes are spectroscopically not resolved due to exchange processes. This allows a first correlation between the complex species observed and the synthetic conditions reported. Furthermore, different preferences to build homo- or heterochiral complexes are detected for binaphthol and biphenol phosphoramidite complexes.     

Characterization of the rutin-metal complex by electrospray ionization tandem mass spectrometry.

According to the strong application background of bioflavonoid and metal-flavonoid complexes, novel electrospray ionization tandem mass spectrometry (ESI-MSn) was applied to investigate the structure and fragmentation mechanism of transition metal-rutin complexes. In the full-scan mass spectra, different stoichiometric ratios of rutin-metal complexes were found. In the reaction between rutin and Cu, four kinds of complexes with four different stoichiometric ratios were produced. In the reaction between rutin and Zn, Mn(II), and Fe(II), only two kind of complexes with stoichiometric ratios of 1:1 and 1:2 occured. In further tandem mass spectrometric experiments of different rutin-metal complexes, product fragments came from the neutral loss of the external rhamnose and the internal glucose unit, oligosaccharide chain, aglycone, and small organic molecules. According to the MSn data, we proposed a mechanism for all fragments of the rutin-Cu complex A and the structure of two rutin-Cu complexes, C and D.     

RAPTA complexes containing N‐substituted Tetrazole scaffolds: Synthesis,characterization and Antiproliferative activity

This work describes the synthesis of a series of Ru(II)‐Arene (Arene=p‐cymene, benzene) complexes using different N‐substituted tetrazole ligands and their PTA analogues. All the complexes have been characterized thoroughly using different analytical techniques. Antiproliferative activity of the synthesized complexes against different cell lines indicates remarkable activity of certain complexes up to nanomolar level. In few cases introduction of water soluble PTA (PTA = 1,3,5‐ triaza‐7‐phospha‐tricyclo‐[3.3.1.1]decane) ligand induce significant cytotoxic activity in the ruthenium complex with respect to their chloro analogues, particularly against Jurkat and MCF‐7 cell lines. Interaction with different biomolecules and stability of the RAPTA complexes have been explored in pseudo‐pharmacological conditions.     

Synthesis, Spectral and Thermal Studies of o-vanillin Oxime Complexes of Zinc(II), Cadmium(II) and Mercury(II)

Zinc(II), cadmium(II) and mercury(II) complexes of o-vanillin oxime have been synthesized and characterized by different physicochemical techniques. All the complexes have been subjected to non-isothermal decomposition studies in nitrogen atmosphere using thermogravimetry. The kinetic parameters for the decomposition of these complexes were evaluated using different methods and comparatively better results were obtained by these different methods. It has also been found that the decomposition processes of all these complexes follow first order kinetics. This revised version was published online in July 2006 with corrections to the Cover Date.     

Structural and bonding characteristics in transition metal-silane complexes

Transition metal-silane complexes containing metal-eta 2-H-Si coordination display different structural and bonding characteristics in comparison to other sigma-complexes, such as dihydrogen and alkane (agostic) complexes. The different characteristics can be related to the strong sigma*-accepting properties of the eta 2-silane ligand(s) because of the weaker H-Si sigma bond. Various examples of metal-silane complexes have been reviewed and their structural stabilities have been systematically discussed. Silyl-hydride complexes having substantial silyl-hydrido interactions have also been emphasized.     

On the nature of the stabilization of benzene···dihalogen and benzene···dinitrogen complexes: CCSD(T)/CBS and DFT-SAPT calculations

The structure and stabilization energies of benzene (and methylated benzenes)···X(2) (X=F, Cl, Br, N) complexes were investigated by performing CCSD(T)/complete basis set limit and density functional theory/symmetry-adapted perturbation theory (DFT-SAPT) calculations. The global minimum of the benzene···dihalogen complexes corresponds to the T-shaped structure, whereas that of benzene···dinitrogen corresponds to the sandwich one. The different binding motifs of these complexes arise from the different quadrupole moments of dihalogens and dinitrogen. The different sign of the quadrupole moments of these diatomics is explained based on the electrostatic potential (ESP). Whereas all dihalogens, including difluorine, possess a positive σ hole, such a positive area of the ESP is completely missing in the case of dinitrogen. Moreover, benzene···X(2) (X=Br, Cl) complexes are stronger than benzene···X(2) (X=F, N) complexes. When analyzing DFT-SAPT electrostatic, dispersion, induction, and δ(Hartree-Fock) energies, we recapitulate that the former complexes are stabilized mainly by dispersion energy, followed by electrostatic energy, whereas the latter complexes are stabilized mostly by the dispersion interaction. The charge-transfer energy of benzene···dibromine complexes, and surprisingly, also of methylated benzenes···dibromine complexes is only moderate, and thus, not responsible for their stabilization. Benzene···dichlorine and benzene···dibromine complexes can thus be characterized merely as complexes with a halogen bond rather than as charge-transfer complexes.     

鱼精蛋白-siRNA不同形貌复合体的制备、 结构及药效学分析

利用涡旋混匀及室温孵育的方法制备了不同形貌的鱼精蛋白-siRNA复合体, 并利用聚丙烯酰胺凝胶电泳结合银染、 原子力显微镜和透射电子显微镜等手段进行了结构表征. 结果表明, 鱼精蛋白可以和不同的siRNA分子以不同的质量比形成球形和纤维状鱼精蛋白-siRNA复合物. 在此基础上, 利用Mg²⁺等金属离子探针, 确认鱼精蛋白与siRNA的磷酸-戊糖骨架之间通过静电力发生作用. 利用原子力和透射电子显微镜表征了鱼精蛋白-siRNA复合体的形貌和结构特征; 利用激光纳米粒度仪测量了该复合体的粒径; 并进一步比较了黑色素瘤细胞对不同形貌复合体的吞噬及药效学特征.     

Electronic Absorption Spectra and Ligand Structure in the Metal Complexes of Quinizarin

The character of the electronic absorption spectra of the metal complexes with 1,4-dihydroxy-9,10-anthraquinone depends on the ligand state, namely, on the degree of its ionization and predominant contribution of the tautomeric 9,10-, 1,10-, and 1,4-anthraquinoid resonance structures. The known complexes are classified in accordance with the ligand structure. The maximal contribution of the 1,10-anthraquinoid structure of the ligand is observed for the majority of monometal complexes, while that of 9,10-anthraquinoid structure is typical of bimetal complexes. Differences in the composite electronic absorption spectra of the mixed-ligand complexes are explained in terms of contribution of different quinizarin tautomeric forms with different degree of ionization.     

Thermal investigation of iron(III) and manganese(II,III) complexes of dianils derived from 6-formylkhellin

Manganese and iron complexes of Schiff bases derived from 6-formylkhellin were prepared and characterized. Complexes of o-phenylenediamine derivative (ligand (I)) are monomeric or dimeric whereas those of p-phenylenediamine derivative (ligand (II)) are polymeric. The complexes obtained are characterized by a lower magnetic moment values. The complexes also have different solvent of crystallization with different nature of interaction. The thermal behaviour of the ligands and their metal complexes was investigated by means of DTA, TG, IR and X-ray diffraction spectroscopy. Ligand (I) shows different thermal behaviour from that of ligands (II) and (III). The complexes of ligand (II) give abnormal oxides as a final product during their thermal decomposition. This revised version was published online in August 2006 with corrections to the Cover Date.     

“眼镜”状碘化亚铜配合物的调光和双光子发光性质

将半柔性的π-不饱和双吡啶端基配体3-pebtd与CuI分别在不同的溶剂中分层扩散, 经自组装得到8种具有Cu₂I₂L₂构型的眼镜状碘化亚铜配合物. 利用X射线单晶衍射、 X射线粉末衍射和元素分析等方法确定了配合物的结构. 对配合物的光物理性质进行了表征, 结果表明, 不同溶剂中自组装得到的配合物的单光子发光均表现出单一荧光峰, 这可归因于卤素到配体的电荷转移( ³XLCT); 并且这些配合物的发光颜色由492 到518 nm可调, 量子产率为33.1%~68.5%. 同时, 这类配合物表现出较优异的双光子发光性质, 有望将其用于生物成像领域.     

Synthetic Methodologies and Structures of Metal-[C60]Fullerene Complexes

A review of the chemistry of transition metal-[C₆₀]fullerene complexes is presented. The main focus is directed toward the different methodologies for obtaining both metal bound and ligand bound complexes of C₆₀, and the different types of structures which have been so far identified for metal-C₆₀ complexes.     

Palladium complexes with picolyl functionalized N-heterocyclic carbene ligands and their application in the Mizoroki–Heck reaction

A series of Pd complexes of picoline-functionalized N-heterocyclic carbenes with different substituents were synthesized. The molecular structures of selected complexes were determined by X-ray diffraction studies, showing a pseudo-square-planar structure with a Pd center surrounded by carbene, pyridine, and two chloride ligands. The influence of the different substituents on the structure and reactivity of the complexes has been studied. The catalytic properties of the complexes were investigated in the Mizoroki–Heck reaction for cross-coupling of bromobenzene with a variety of aryl halides. Their performances varied in these reactions but showed good product regioselectivities.     

Terahertz absorption spectra of some saccharides and their metal complexes

In this work, THz absorption spectra of some saccharides and their metal complexes were measured. The main purpose of this work is to investigate the M-O vibrations, intermolecular and intramolecular hydrogen bonds and other vibrations in the FIR region using powerful spectroscopic techniques adopting the metal-sugar complexes prepared in our laboratory. The M-O vibrations in the FIR spectra of metal-sugar complexes indicate the formation of metal complexes. The THz spectrum of glucose below 100cm(-1) was measured at first to confirm the THz experimental method. Characteristic absorption bands in the spectra of various samples are observed. THz spectra of saccharides below 100cm(-1) often have several absorption bands, and different saccharides have various absorption peaks in the THz region, which may be used to distinguish different saccharides. The differences in the number of bands observed are related to different structures of the samples, and these absorption bands are related to the collective motion of molecules. But the THz spectra of their metal complexes are different from the ligands, and no band appears in the region below 50cm(-1) at the present experimental condition, which indicates that THz spectroscopy may also be helpful to identify the formation of metal-sugar complexes, and the changes after complexation in the THz spectra below 100cm(-1) may be related to different metal ions. The metal-sugar complexes with similar crystal structures resemble mid-IR spectra, but their THz spectra may have some differences.     

A comparison of data analysis methods for determining gas phase stabilities by cid: Alkali metal complexes of polyether ionophore antibiotics

The gas phase stabilities of Group I metal complexes of the polyether ionophore antibiotics lasalocid and monensin were investigated by collision induced dissociation mass spectrometry. Electrospray ionization was used with a triple quadrupole mass spectrometer for the determination of threshold dissociation energies upon application of increasing collision energies. Various data analysis techniques for the determination of dissociation energies are discussed to assess the most suitable method for determining the stabilities of the ionophore-metal complexes studied here. In all cases only the relative stabilities of different complexes may be obtained by the method presented in this study, which does not assess absolute gas phase dissociation energies. Correction factors have been applied, however, to account for the energy conversion during collisions of different metal complexes and the varying degrees of freedom of different sized ligands, allowing for the comparison of the stabilities of different ionophores with like-metals. The measured threshold dissociation energies were compared with respect to the ionic radius of the metal cation, revealing a maximum stability for the K+ complexes of both lasalocid and monensin. A striking decrease in the stabilities of the Rb+ and Cs+ complexes was observed and is believed to be related to a decreasing degree of coordination that the ionophores can accomplish with the larger metals.     

Reactions of coordinated ligands in uranyl hydroxylaminate complexes

The reactions of coordinated ligands in uranyl complexes were studied for the first time. The reaction of uranyl hydroxylaminate complexes with aldehyde and ketones of different structure was shown to result in the formation of corresponding oxime complexes.     

廉价金属配合物催化的C-C与C-N键构建研究进展

综述了廉价金属铁、钴、锰等配合物催化的C-C与C-N键构建的研究进展。廉价金属配合物在催化反应中表现出不亚于贵金属配合物的催化活性,而且具有价格低廉、无毒等优点,因此成为近年来研究的热点。本文主要从廉价金属配合物催化的C-C键与C-N键的合成等方面进行总结,为今后廉价金属配合物的研究提供参考。     

Preparation and Characterization of Polymer－Supported Rare Earth Complexes

ＰｒｅｐａｒａｔｉｏｎａｎｄＣｈａｒａｃｔｅｒｉｚａｔｉｏｎｏｆＰｏｌｙｍｅｒ－ＳｕｐｐｏｒｔｅｄＲａｒｅＥａｒｔｈＣｏｍｐｌｅｘｅｓＹＵＧｕａｎｇ－ｑｉａｎａｎｄＬＩＹｕ－ｌｉａｎｇ（ＣｈａｎｇｃｈｕｎＩｎｓｔｉｔｕｔｅｏｆＡｐｐｌｉｅｄＣｈｅｍｉ...     

Mössbauer and positron annihilation studies of microstructural peculiarities of iron-dextran complexes

The microstructural peculiarities of pharmaceutically important iron-dextran complexes were studied by Mössbauer and positron annihilation techniques. The results of Mössbauer spectroscopy showed variations of the iron cores in iron-dextran complexes containing different forms of FeOOH and different electronic and magnetic states of iron. The results of angular correlations of annihilation radiation and positron life-time spectroscopies showed microstructural variations of the dextran shell of the iron-dextran complexes.