Catalytic Effect of Transition Metal Complexes of Triaminoguanidine on the Thermolysis of Energetic NC/DEGDN Composite

The transition metal complexes of triaminoguanidine(TAG-M,where M=Cobalt(Co)or Iron(Fe))have been prepared.The catalytic effect of these complexes on the thermolysis of energetic composite based on nitrocellulose and diethylene glycol dinitrate,has been investigated.Extensive characterization of the resulting energetic composites was carried out using scanning electron microscopy(SEM),X-ray diffraction(XRD),Fourier transform infrared spectroscopy(FTIR),and differential scanning calorimetry(DSC).Isoconversional kinetic analysis was performed to determine the Arrhenius parameters associated with the thermolysis of the elaborated energetic formulations.It is found that TAG-M complexes have strong catalytic effect on the thermo-kinetic decomposition of NC/DEGDN by decreasing the apparent activation energy and significantly increased the total heat release.The models that govern the decomposition processes are also studied,and it is revealed that different reaction processes are accomplished by introduction metal complexes of triaminoguanidine.Overall,this study serves as a valuable reference for future research focused on the investigation of catalytic combustion features of solid propellants.

Synthesis and Physico-Chemical Characterizations of Novel Hydrazone Ligands and Their Metal Complexes against Hormone-Dependent and Independent Cancers

This work deals with the synthesis and physicochemical characterizations of a new group of novel retinoidal ligands and their metal complexes. Their in vitro anti-proliferative activities have shown that ligand L1 is effective against human breast cancer BT-20 and MCF-7 cell lines. At the same time, compound L2 exerts its effect on human prostate cancer PC-3 and human breast cancer MDA-MB-231 and MCF-7 cell lines respectively. The retinoid ligands exert their pleiotropic action toward retinoic acid receptors (RARs) than their metal complexes but all compounds exhibit concentration-dependent.

Inhibition of cysteine protease papain by metal ions and polysulfide complexes,especially mercuric ion

Aim Cysteine proteases are closely associated with many human and non-human pathological processes and are potential targets for metal ions especially Hg^2＋ and the related species. In the present work, on the basis of to the general study on the effects of some metal ions on the activity of papain, a well-known representative of cysteine protease family, the inhibitory effects of Hg^2＋ and polysulfide complexes were studied. Results All the metal ions tested （Hg^2＋, Cu^2＋, Ag^＋, Au^3＋, Zn^2＋, Cd^2＋, Fe^3＋, Mn^2＋, Pb^2＋, Yb^3＋） inhibit the activity of papain anda good correlation between the inhibitory potency and softness-and-hardness was observed. Among the metals, Hg^2＋ was shown to be a potent inhibitor of papain with a Kiof 2 × 10^-7 mol·L^-1 among. Excessive amounts of glutathione and cysteine could reactivate the enzyme activity of papain deactivated by Hg^2＋. These evidences supported that Hg^2＋ might bind to the catalytic site of papain. Interestingly, Hg （Ⅱ） polysulfide complexes were for the first time found to inhibit papain with a Ki of 7 × 10^-6 mol·L^-1, whose potency is close to a well known mercury compound, thimerosal （Ki=2.7 × 10^-6）. In addition, Hg （Ⅱ） polysulfide complexes exhibit good permeability （ 1.9 × 10-5 cm· s^-1） to caco-2 monolayer. Conclusion These results suggested that mercury polysulfide complexes might be potential bioactive species in the interaction with cysteine proteases and other- SH-content proteins, providing a new clue to understand the mechanism of the toxicological and pharmacological actions of cinnabar and other insoluble mercury compounds.

Highly active double metal cyanide complexes: Effect of central metal and ligand on reaction of epoxide/CO2

Various novel double metal cyanide （DMC） catalysts were successfully prepared by modifying the central metal （M） and one of cyanide ion （CN-） in Zna[M（CN）b]c complex. Such modifications have significant impact on the catalytic efficiency as well as the polymer selectivity for the reaction of PO/CO2. Zn-Ni（Ⅱ） DMC is a potential catalyst for alternating copolymerization of PO/CO2,and DMC catalysts based on Zn3[Co（CN）5X]2 （X = Br^- and N3^-） exhibit moderate efficiency for the production of polycarbonates.This research presents the preliminary exploration of novel DMC complex via chemical modification of its central metal and ligand.

Metal 2-Hydroxy-1-Naphthaldehyde Thiosemicarbazone (Me-HNT) Complexes-A New Kind of Biomimic Enzyme Catalyst

Metal (Me=Fe(III), Mo(VI), Mn(II), Co(II), Ni(II), Zn(II) and Cu(II)) 2-hydroxy-1-naphthaldehyde thiosemicarbazone complexes (MeHNT) were synthesized and used as mimic-enzyme catalysts to mimic the active group of horseradish peroxidase (HRP). The results showed that Fe-HNT, Mo-HNT are effective catalysts, which have similar catalytic activity as HRP. The sequence of catalytic activities of tested biomimic peroxidas is Mo-HNT > Fe-HNT > Zn-HNT > Ni-HNT > Mn-HNT. Among them, Fe-HNT is used as a mimic-enzyme catalyst in determination of ascorbic acid and glucose by coupling the catalytic reaction of glucose oxidase.

Synthesis of Schiff bases of naphtha[1,2-d]thiazol-2-amine and metal complexes of 2-(2'-hydroxy)benzylideneaminonaphthothiazole as potential antimicrobial agents

Objective： A series of 2-benzylideneaminonaphthothiazoles were designed and synthesized incorporating the lipophilic naphthalene ring to render them more capable of penetrating various biomembranes. Methods： Schiff bases were synthesized by the reaction of naphtha[1,2-d]thiazol-2-amine with various substituted aromatic aldehydes. 2-（2＇-Hydroxy）ben- zylideneaminonaphthothiazole was converted to its Co（Ⅱ）, Ni（Ⅱ） and Cu（Ⅱ） metal complexes upon treatment with metal salts in ethanol. All the compounds were evaluated for their antibacterial activities by paper disc diffusion method with Gram positive Staphylococcus aureus and Staphylococcus epidermidis and Gram negative Escherichia coli and Pseudomonas aeruginosa bacteria. The minimum inhibitory concentrations of all the Schiff bases and metal complexes were determined by agar streak dilution method. Results： All the compounds moderately inhibited the growth of Cram positive and Gram negative bacteria. In the present study among all Schiff bases 2-（2＇-hydroxy）benzylideneaminonaphthothiazole showed maximum inhibitory activity and among metal complexes Cu（Ⅱ） metal complex was found to be most potent. Conclusion： The results obtained validate the hypothesis that Schiff bases having substitution with halogens, hydroxyl group and nitro group at phenyl ring are required for the antibacterial activity while methoxy group at different positions in the aromatic ring has minimal role in the inhibitory activity. The results also indicated that the metal complexes are better antibacterial agents as compared to the Schiff bases.

Synthesis and Liquid Crystal Properties of Transition Metal Complexes of Meso-tetra(4-n-myristyloxyphenyl)porphyrin

Transition metal complexes of meso-tetra(4-myristyloxyphenyl)porphyrin TMPPM [M =Mn, Fe, Co, Ni, Cu, Zn; TMPP=mesotetra(4-myristyloxyphenyl)porphyrin] have been synthesized and characterized by means of elemental analyses, UV-Vis spectra, infrared photoacoustic spectra, 1H NMR spectra, molar conductance and differential scanning calorimetry(DSC). The ligand and the Zn complex show liquid crystalline behavior. According to the DSC thermogram of the Zn complex, it exhibits a lower phase transition temperature -7.453 ℃ and a wide mesophase temperature span, 77 ℃.

Simultaneous Removal of Surfactant Template from MCM-41 and Implantation of Transition Metal Complexes into Mesopores with Supercritical Fluid

The simultaneous removal of up to 92% of the surfactant template and chemical implantation of transition metal complexes into mesopores has been successfully achieved by treating as-synthesized pure siliceous MCM-41 with supercritical CO2 modified with CH2Cl2/MeOH mixture, resulting in the formation of functionalized material with uniform pore structure.

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.

Synthesis and Crystal Structure of the Novel Chiral o-Hydroxyphenyloxazoline Metal Complexes

The chiral o-hydroxyphenyloxazoline ligands were synthesized and their metal complexes with Cu, Ni and Ti were prepared. The crystal structure of complex 2a formed by ligand 1a with Cu (molar ratio 2:1) was determined by single-crystal X-ray diffraction analysis, and it belongs to monoclinic, space group P21 with a = 11.679(2), b = 17.681(4), c = 12.838(3) ? b = 106.50(3), C26H32N2O4Cu, Mr = 500.08, V = 2541.8(9) 3, Z = 4, F(000) = 1052, Dc = 1.307 g/cm3, m = 0.892 mm-1, the final R = 0.0448 and wR = 0.0930 (I > 2s(I)). In the asymmetric unit of complex 2a, there exist two types of molecules which are self-associated by intermolecular O…Cu interactions, and 揹imeric complex?is thus formed. The distances of the Cu and O atoms of a pair of intermolecular coordinated molecules are 2.828 ?for Cu(1)…O(21) and 2.776 ?for Cu(2)…O(13), respectively. The coordination N and O atoms and the central Cu are slightly deviated from coplanarity.

Synthesis and characterization of a novel schiff base metal complexes and their application in determination of iron in different types of natural water

A novel, simple approach to the synthesis of macrocyclic Schiff base ligand resulted from the condensation of bisaldehyde and ethylenediamine was prepared (7, 8, 15, 16, 17, 18-hexahydrodibenzo (a, g) (14) annulene) (L) and its complexes were synthesized and characterized using different physicochemical studies as elemental analysis, FT-IR, 1H NMR, conductivity, magnetic properties, thermal analysis, and their biological activities. The spectroscopic data of the complexes suggest their 1:1 complexe structures which are investigated by elemental analysis, FT-IR, 1H NMR, conductivity, magnetic properties, thermal analysis, and their biological activities. The spectroscopic studies suggested the octahedral structure for the all complexes. The spectroscopic data of the complexes suggest their structure in which (N2O2) group act as a tetradentate ligand and two chlorides as monodentate ligands. Also electronic spectra and magnetic susceptibility measurements indicate octahedral structure of these complexes. The synthesized Schiff base and its metal complexes also were screened for their antibacterial and antifungal activity. Here we report the effect of a neutral chelating ligand on the complexation with iron to determine it in different types of natural water using recovery test. The activity data show that the metal complexes to be more potent/ antibacterial than the parent Schiff base ligand against one or more bacterial species.

Microwave Preparation and Spectroscopic Investigation of Binuclear Schiff Base Metal Complexes Derived from 2,6-Diaminopyridine with Salicylaldehyde

The binuclear Schiff base complexes prepared by condensation 2,6-diamino-pyridine and salicylaldehyde (LH) by using microwave and adding metal salts to ligand by same ratio. The Schiff base ligand was checked by infrared, electronic spectra and 1HNMR spectroscopy and prepared complexes characterized by molar conductivity, infrared, electronic spectra and susceptibility measurements. The values of molar conductivities reveal that the complexes are non-electrolytes, from obtained data of electronic spectra and magnetic moment, an octahedral geometry was suggested, coordinated to the metal ions in a manner with N donor sites of imine groups, and oxygen of phenolic OH group.

Synthesis and Characterization 9-tungstosilicate Complexes with Transition Metal

The title complexes KaHb[M(SiW9O34)2]?mH2O(M=Ni,Cu,Zn,Fe or Mn) were synthesized by SiW9O34 10? with transition metal respectively and their structure were characterized by mean of elemental analysis, TG-DTA, IR spectra and, UV spectra. In addition, their redox properties in solution were investigated using polarographic and cyclic voltammographic methods. Experimental results indicated that the complexes have Keggin structure and that the heteropolyanions underwent two-step, two-electron tungsten reduction processes.

Synthesis and Spectroscopic Characteriration of Transition MetalComplexes of Maleionitriledithiolene and 1,10-Phenanthroline

The title complex M (mnt) (phen), M=Fe11, Co11. Ni11, Cu11. Zn11. was respectivelysynthesized by reaction of disodium maleionitriledithiolate (Na2 (mnt) ) with corresponding metalcomplex M (phen) Cl2. Charge transfer transitions in the absorption and emission spectra have beenstuded.

Study on Property of Salicylaldehyde Schiff Base Metal Complexes for Catalytic Oxidation of Model Sulfides

Seven kinds of Schiff base metal complexes(C1-C7)were synthesized by the reaction of substituted salicylaldehyde Schiff base with cobalt nitrate,nickel nitrate,and copper nitrate,respectively.The oxygen carrying performance,and the catalytic property of complexes for the oxidation of model sulfides 1-hexanethiol,dibutyl sulfide,and 2-methylthiophene along with their influencing factors were explored,while the oxidized products of the model sulfides were also analyzed and characterized.The results show that the catalytic oxidation property of the complexes is determined by their oxygen carrying performance and solubility in n-octane.The oxygen carrying performance of the complexes is mainly affected by the central ion species,the electronic effects,and the spatial effects of the substituents as well as the degree of conjugation.More specifically,the oxygen carrying performance can be improved by enhancing the oxygenation capacity of the central metal ions,increasing the electron donating ability of the ligand substituent,and diminishing the steric hindrance as well as extending the conjugated chain.Complexes C7 were found to be with high oxygen carrying capacity and high solubility in n-octane,which shows the best catalytic oxidation property,and the oxidation conversion rates for 1-hexylthiol,dibutyl sulfide,and 2-methylthiophene are 74.2%,65.1%,and 22.7%,respectively.Upon using the oxidation catalyst of Schiff base metal complexes,three sulfides can be oxidized by oxygen to form sulfones and sulfoxides.1-Hexanethiol and dibutyl sulfide will continue to be oxidized to form sulfates and sulfites.

Synthesis, Characterization and Biological Activity of Sodium Barbitone-Group-VIII Metals (viz. Ni(II), Pd(II) and Pt(II)) Complexes

This work aims to characterize, synthesize and evaluate the biological activity of sodium barbitone and their metal chelates Ni(II), Pd(II) and Pt(II). The new synthesized metal chelates are investigated by elemental analysis, IR, mass spectra, thermal analysis and biological activity. Square planer structure of the prepared complexes obtained from the result of analysis. The antibacterial and antifungal of sodium barbitone ligand and its conforming metal chelates were screened against bacterial species Gram positive (Staphylococcus aureus), Gram negative bacteria (Escherichia coli) and fungi Aspergillus flavus and Candida albicans fungi. Ampicillin and amphotericin were used as references for antibacterial and antifungal studies. The activity data show that the platinum group metals chelates have activity data show that some of the platinum group metals (viz. Pt(II) and Pd(II)) chelates have a promising biological activity comparing to sodium barbitone parent free ligand against bacterial and fungal species.

Synthesis, Spectroscopic, Molecular Modeling and Anti-Fungal Studies of Some Divalent Metal Complexes of 4-Hydroxyacetophenone Isonicotinoyl Hydrazone

A novel ligand N-4-hydroxyacetophenone isonicotinoyl hydrazone and its manganese(II) and nickel(II) metal complexes have been synthesized. The synthesized Schiff base and its metal complexes have been characterized by physical state determination, melting point and solubility measurements in different solvents, infrared, proton nuclear magnetic resonance, mass spectrometric and powder X-ray spectroscopic techniques. The thermal properties of the prepared compounds were obtained from TG/DTG measurements. On the basis of the analytical techniques, the ligand was found to be bidentate in nature coordinating to the metal ions through the azomethine nitrogen and carbonyl oxygen atoms leading to distorted octahedral geometries of the metal complexes which were modeled using MM2 force field. The ligand and its metal(II) complexes were evaluated for antifungal activity against Aspergillus fumigatus, Aspergillus niger, Candida albicans and Rhizopus stolonifera. The antifungal evaluation results revealed an enhanced activity upon coordination of the ligand with the metal(II) ions. The activity of the metal complex to the tested fungal strains was in the order Ni(II) > Mn(II).

Syntheses and Structural Characterizations of η~5-2,4-Cyclopentadien-1-yl Di-carbonyliron Heteronuclear Bi-Metallic Complexes

The novel complexes, Cp(CO) 2FeTiCp 2Cl(1) and Cp(CO) 2FeSn(CH 2CMe 2Ph) 3(2), were synthesized and characterized by means of elemental analyses and IR spectra, Cp(CO) 2FeSn· (CH 2CMe 2Ph) 3 was additionally characterized by X ray crystal structure analysis. The results of the elemental analyses are in good agreement with the theoretical values. The IR spectra show the existence of η 5 2,4 cyclopentadien 1 yl, carbonyl and methyl groups in the title complexes. The above experimental results show that the M-M bond exists in Cp(CO) 2FeSn· (CH 2Me 2Ph) 3, while the existence of the M-M bond in Cp(CO) 2FeTiCp 2Cl is highly possible, too. Both the two complexes are rather stable towards air and moisture, easily soluble in tetrahydrofuran and toluene, while their solubilities are greatly different in n hexane.

5,10,15,20-Tetrakis(p-4-fluorobenzoyloxy)phenyl Porphyrin and Its Transition Metal Complexes

The properties of porphyrins can be changed through the choice of peripheral substituents and inserted metal ions. To obtain porphyrin complexes with novel structures, 5,10, 15,20-tetrakis（p-4-fluorobenzoyloxy） phenyl perphyrin（TFBOPPH2 ） and its transition metal complexes {TFBOPPM [ M = Mn（ Ⅲ ）, Fe（ Ⅲ ）, Co（ Ⅱ ）, Ni（ Ⅱ ）, Cu（ Ⅱ ） and Zn（ Ⅱ ） ] } were synthesized and characterized by means of UV-Vis, IR photoacoustic speetrumetry, ^1H NMR, elemental analyses, molar conductance, and XPS methods. A structure is proposed, in which one porphyrln molecule is coordinated with a transition metal ion in a tetradentate fashion, while the chlorine ion is the balaneeable anion in Fe（ Ⅲ ） and Mn（ Ⅲ ） complexes.

Cleavage of Nucleotides by Lanthanide Metal Complexes

The present work revealed that the praseodymium()complex of 2carboxyethylgermanium sesquioxide(Ge132)promotes the hydrolysis of the phosphodiester linkages of 3,5cyclic adenosine monophosphate(cAMP),3,5cyclic deoxyadenosine monophosphate(dcAMP),5adenosine monophosphate(5AMP)and 5deoxyadenosine monophosphate(5dAMP)under mild conditions.Both cAMP and dcAMP were hydrolyzed sitespecifically,yielding predominantly 3monophosphates,the main products of the cleavage of 5AMP and 5dAMP included adenosine(Ado),deoxyadenosine(dAdo)and free phosphates respectively.A hydrolytic mechanism was proposed for cAMP,dcAMP,5AMP and 5dAMP.