Dioxygen Affinities and Biomimetic Catalytic Performance of Transition-metal Complexes with Crowned Bis-Schiff Bases

It is well known that Cosalen can reversibly adsorb oxygen so that it can be used to separate, condense oxygen and catalyze oxidation reactions. Thus, this kind of complexes has received much attention recently1,2. But these complexes are easy to dimerize and lose activities after adsorbing oxygen molecule3,4. Avdeef and coworkers5 demonstrated that it would be favorable to form stable 1:1 oxygen adducts when these Co(II) complexes were modified by the substituents. So many new species subst…     

Determination of Nickel and Palladium in Environmental Samples by Low Temperature ETV-ICP-OES Coupled with Liquid-liquid Extraction with Dimethylglyoxime as Both Extractant and Chemical Modifier

A novel method for the determination of nickel and palladium in environmental samples by low temperature ETV-ICP-OES with dimethylglyoxime(DMG)as both the extractant and chemical modifier has been developed.In this study,it was found that nickel and palladium can form complexes with dimethylglyoxime(0.05%,mass fraction)at pH 6.0 and can be extracted into chloroform quantitatively.The complexes can be evaporated into plasma at a suita-ble temperature(1400 ℃)for ICP-OES detection.Under the optimized conditions,the detection limits of nickel and palladium are 0.48 and 0.40 ng/mL,respectively,while the RSD values are separately 5.0% and 3.1%(ρ=50 ng/mL,n=7).The proposed method was applied to the determination of the target analytes in environmental samples with satisfactory results.     

Synthesis and Crystal Structure of a New Chain Coordination Polymer [Cu（inio）2（H2O）]∞ （Inio = Isonicotinic Acid N-Oxide）

1 INTRODUCTION With deep studies on the complex biology system and syntheses of new functional complexes, people have paid more and more attention to the polynuclear complexes. In the construction of one to three dimensional frameworks, multi-dentate ligands are usually used to bridge the metal centers to form polymeric structures[1, 2]. The isonicotinic acid N-oxide can function as a good mono-dentate ligand[3～8] through one oxygen atom from the group of -NO or carboxyl, and the dep…     

Synthesis and Crystal Structure of a New One-dimensional Double Helical-chain Polymer, {Zn（O2CC12H8CO2）（H2O）}n

1 INTRODUCTION Pronounced interest has been put in the field of coordination polymeric complexes owing to their fas- cinating molecular topologies[1～3] along with poten- tial applications as functional materials[4～6]. In par- ticular, complexes with helical structures attract much attention of scientists[7, 8] mainly due to their simi- larity to the structure of DNA molecule. To obtain new complexes, solv- and hydrothermal routes are currently used. In this way, the organic ligand act…     

Synthesis and Structure of Bis（indene—1,2,3—trione 2—oximato）bis （aqua）Mn（Ⅱ）：Mn（C9H4NO3）2（H2O）2

1 INTRODUCTION The interest in the complexes of transition metals with ligands ketoxime[1, 2] as potential models for metal binding sites in ferroverdin[3, 4] has prompted the investigation on the structures and the overall coordination geometry of the metal centers in these complexes. Oxime derivatives are interesting ligands since the ketoximes are found to chelate transition metals through the N (oxime) and O (ketone) atoms[5, 6]. However, monodentate coordination via only one O or …     

Synthesis and Crystal structure of [（Praseodymium）2（3,5—Binitro benzoyloxy）6（Dimethyl Sulfoxide）4]Complex

1 INTRODUCTION The polynuclear lanthanide complexes are specially interested and widely applied in the researches on light, electricity and magnetism[1～4], and the studies of the synthesis of polynuclear lanthanide complexes and its applications tend to be growing rapidly nowadays. Herein a report on the synthesis process and crystal structure of the title complex is presented. The crystal structure showed it is a non-electrolyte complex with one- dimensional chain. OCCOOPrOOCPr…     

A Theoretical Study on the Stereoisomerism in the Complex of Cucurbit[8]uril with 2,6-Bis(4,5-dihydro-1H-imidazol-2-yl)naphthalene

Cucurbit[n]urils (CB [n]),macropolycyclic compounds self-assembled from an acid-catalyzed condensation of glycoluril and formaldehyde1, can form inclusion complexes with a number of organic substrates in water2. Usually, CB [6] is used in the studies because of its easy synthesis, and the driving forces for its binding are considered to be the hydrophobic effect and dipole-dipole interactions. CB[n] 1Very recently, Kim et al reported the synthesis of CB [5], CB [7], and CB [8]3. They fou…     

Synthesis and Crystal Structure of 4-（4,6-dimethoxyl -pyrimidin-2-yl）-3-thiourea Carboxylic Acid Methyl Ester

1 INTRODUCTION Pyrimidinyl thioureas have been studied for many years because of their broad antibiosis and sterilibza- tion properties. Recent years’ study shows that pyri- midinyl thioureas not only can be used to kill insects and adjust plant growth, but also have anti-viral ac- tivities[1, 2]. From our early quantum study on these compounds, we find that they have several active cen- ters and can form polyligand complexes with metals easily[3]. These complexes are widely used as ant…     

Synthesis and Crystal Structure of Bis-(2,2'''' bipyridyl)-2-pyrimidinethiolate-Ni(Ⅱ) Complex

1 INTRODUCTION The design of metal complexes of bipyridine is one of the most highlighting topics in molecular materials with specific optical, electronic and mag- netic properties. What studied and well-documented most widely are those of the d6 metal polypyridines, and so are the d8 and d10 metal complexes with rich luminescence behaviour[1] very recently, which can be beneficial to the design of unique functional ma- terials. Currently our interest is to design lumine- scent heteronuc…     

Synthesis, Characterization, Spectroscopy and Study of Antimicrobial Properties of Two New Substituted Trichloroaluminate（Ⅲ） Complexes [AlCl3X]- （X = SCN-, CN-）

The synthesis and characterization of two new aluminate(Ⅲ) complexes with general formula K[AlCl3X] are reported. These compounds derived from aluminate trichloride and related salts. Potassium trichlorothiocyanoaluminate, PCTA, and potassium trichlorocyanatoalu-minate, PCCA, are two new ionic aluminate complexes. They can be easily synthesized in a nearly quantitative yield by using the direct reaction of AlCl3 and KX. The complexes were characterized by physico-chemical and spectroscopic methods. Theoretical calculations have been used for the extraction of structural and spectroscopic data of these new synthesized complexes. The antibacterial activities of such compounds were studied against the Staphylococcus aureus, Escherichia coli, Staphylococcus Epidermidis, Estreptococo B and Shigella.     

Synthesis and Structure of [Cu2（μ—NO2）（aepy）4]（ClO4）3 （aepy=2—（2—Aminoethyl）pyridine）

1 INTRODUCTION There has been great and considerable interest in the study of copper nitrite complexes because they are relevant to the study of copper-containing enzymes involved in the denitrification process[1]; in particular, copper-nitrite complexes are potentially relevant to the nitrite reductases[2] (the enzyme from Achromobacter Cycloclastes) which convert NO2－ to NO and/or N2O. Many attempts have been made to synthesize a variety of copper-nitrite complexes, in which the n…     

Synthesis and crystal structure of complex of Ce(NO_3)_3 with N-(3-methyl-pyridin-2-yl)-formimidoyl-(3-methyl-pyridin-2-yl) hydrazone

Rare earth complexes with organic ligands have been used as luminescence-material usually. Except their luminescent property, the complexes of trivalent lanthanide ions have low toxicity and powerful para-magnetic properties[1,2], so the lanthanide complexes are associated with important biological uses as diag-nostic tools and medicines[36]. Recently, there are some reports on Ce(III) complexes, some of which show anti-cancer activities[7]. S- tetrazines can be used as poly-dentate chelatin…     

Bond Valence Sum Analysis of Tl（Ⅰ） and Tl（Ⅲ） Complexes with O and N Donors

The influence of the lone pair of electrons in thallium complexes is analyzed using the bond valence sum method.Bond length data for metal-organic Tl complexes were obtained from the Cambridge Structural Database(CSD),and problems with searching the CSD file for Tl complexes are discussed.The recommended R0 values for Tl(Ⅰ)-O of 2.162 ,Tl(Ⅲ)-O of 2.016 ,Tl(Ⅰ)-N of 2.286 ?,and for Tl(Ⅲ)-N of 2.014  used with b = 0.37 were derived from analyses of homoleptic Tl-O,Tl-N,and heteroleptic Tl-O and-N metal organic complexes.These R0 values can be used to assign correctly the oxidation state of Tl in complexes containing any combination of Tl-O or Tl-N bonds.Examples of questionable oxidation states for Tl complexes are given.The R0 value for Tl(Ⅲ)-Cl of 2.300  was also determined.     

Synthesis and Crystal Structure of Chloro(p-toluidine)[4-(p-tolyl)imino-2-pentanone-3-oximato]- palladium(Ⅱ), PdCl(p-CH_3C_6H_4NH_2)(p-CH_3C_6H_4-iai)

1 INTRODUCTION Transition metal complexes of N-R-isonitroso- b-ketoimine have received considerable interest, because the isonitroso (oximo) group can coordinate to metal atoms through its oxygen and/or nitrogen atoms to form several geometrical isomers[1～4]. Some palladium(Ⅱ) complexes with N-R-isonitro- soacetylacetoneimine (abbreviated to R-Hiai)[4] and N-R-isonitrosoethylacetoacetate (abbreviated to R- Hieai)[5] have been reported. Here we will report the structure of a palladi…     

Synthesis and Crystal Structure of a New Salen Complex

Salen Schiff base complexes are some of the most important stereochemical models in transition metal coordina tion chemistry, with their ease of preparation and structural variation. [1] Salen complexes are extensively used as organic reaction catalysts, it was reported to be used in asymmetric cyclopropanation, epoxidation, aziridination, hydrolysis, alkylation, Diels-Alder reaction, reduction, oxidation etc. Here we report the synthesis and structure of a new salen nickel complex 4.     

Synthesis and Application of Novel Chiral Poly-nuclear-Mn(III) Catalysts on Asymmetric Epoxidation of Alkenes.

The interest of the coordination chemistry of manganese has been driver by the important roles of metalloenzymes and highly valuable catalysts in olefin expoxidation.1 Jacobsen Salen-Mn complexes with a simple structure have been commercially utilized to catalyze asymmetric epoxidation of unfunctionalized cis-alkenes2, but the catalytic enantioselectivity for trans-alkenes, unfortunately, are lower and this kinds of complexes are unstable and difficult to be recovered for reuse.3 In order to i…     

Simultaneous Laser Thermal Lens Spectrometric Determination of Trace Platinum and Palladium in an Aquesous Solution

A selective and sensitive method for determination of platinum and palladium(Ⅱ）in an aqueous solution simultaneously by laser thermal lens spectrometry,based on the complex reaction of 2-(3,5-dichloropyridylazo)-5-dimethylaminoamiline(3,5-diCl-PADMA) with platinum and palladium,has been developed.It is shown that the palladium complex can be fromed at room temperature, while the platinum complex can be only formed after being heated in a boiling water bath.By using this difference of reaction temperature and the characteristic of the complexes mentioned above,the method for simultaneous determination of platinum and palladium was established in an aqueous solution without a pre-separation.The results show that the dynamic linear ranges of determination for platinum and palladium are 0.005-0.04μg/mL and 0.005-0.25μg/mL respectively,and that the detection limits are both 0.002/μg/mL.The method has been applied to the determination of platinum and palladium simultaneously in alloy and catalyst samples with satisfactory results.     

A Thermochemical Study of the Reaction of Lanthanum Nitrate with Alanine

IntroductionRare earth ions possess some special functions, in biochemistry and can be used as aprobe to label the calcium ion, moreover, amino acids are the structure unit of proteins, so itis very important to make research on the complexes of rare earth salts with amino acids. Theresearch on the behaviour of the complexes of rare earth salts with amino acids has become aheated point of the research in the crossing field of chemistry and biology in recent years['--'].In order to guide the de…     

Synthesis and Structure of [Er4（μ3—OH）4（Hpro）4（Pro）2（H2O）7]（ClO4）6.7H2O

1 INTRODUCTION The design and synthesis of polynuclear com- plexes have attracted chemists?attention in the contemporary chemistry, since their clusters maybe lead to novel materials with magnetic, optical, electronic and catalytic properties of the constituent metals[1～3]. It is also prevalently interesting to synthesize high-nuclearity metal complexes for their nanoscopic dimensions[3, 4]. Spectroscopic properties of the lanthanides are widely used in the study of biological systems. …     

Influence of chelate ring size on the properties of phosphine-sulfonate palladium catalysts

Phosphine-sulfonate based palladium is one of the most extensively studied catalyst systems in olefin polymerization.This type of catalyst features six-membered chelate ring size,and can enable the copolymerizations of ethylene with a wide variety of polar monomers.In this contribution,we decide to investigate the influence of chelate ring size on the properties of phosphinesulfonate palladium catalysts.As such,a series of phosphine-sulfonate ligands and the corresponding seven-membered ring Pd(II)complexes[κ~2-(P,O)-2-(CH_2-PR_1R_2)-4-methylphenyl-sulfonato]Pd(Me)(DMSO)(Pd1,R_1=R_2=Cy,Pd2,R_1=R_2=o-Me O-C_6H_4;Pd3,R_1=Ph,R_2=2-[2,6-(Me O)_2C_6H_3]C_6H_4;DMSO=dimethyl sulfoxide)were designed,prepared and characterized.These palladium complexes are moderately active when they were applied in ethylene polymerization and copolymerizations with methyl acrylate and butyl vinyl ether.However,their properties are greatly reduced from those of the classic six-membered ring phosphine-sulfonate palladium complex Pd2′.The experimental results indicate that the bigger chelate ring size can increase the ligand flexibility and damage the catalytic properties for the phosphine-sulfonate type palladium catalysts.