Synthesis and magnetic properties of one-dimensional Mn(II) complexes linked by dithiooxalato

Three dithiooxalato (Dto) bridging one-dimensional Mn(II) complexes [Mn(L)Dto](L = Phen (1), Bpy (2) and en (3)) were synthesized. All of the complexes have the similar one-dimensional structure through Dto bridge. The measurement of the variable temperature magnetic susceptibility of complex 1 showed that there are weak antiferromag-netic interactions between the Mn(II) ions.     

Crystal structure and surface photo-electric property of Mn（Ⅱ） coordination supramolecules

Two Mn（Ⅱ） coordination supramolecules, [Mn2（C8HTO2）4（phen）2（p-H20）] （1） and [Mn2（btec）（phen）2（H2O）6]·2H2O （2） （phen=1,10-phenanthroline, H4btec=1,2,4,5-benzenetetracarboxylic acid）, were synthesized by hydrothermal method. The crystal structures of the complexes were determined by X-ray single crystal diffraction. The result indicates that （1） and （2） are both binuclear Mn（Ⅱ） complexes. The existence of hydrogen bonds makes the binuclear complexes become further connected to coordination supramolecules, which possess 1D and 3D infinite structures respectively. The complexes were identified by IR, UV-Vis, surface photovoltage spectrum （SPS） and field-induced surface photovoltage spectrum （FISPS）. The results of SPS for the complexes indicate that they both exhibit positive surface photovoltage response bands in the range of 300-600 nm. The SPS phase spectrum and FISPS of complexes indicate that they show certain p-type semiconductor characteristic. However, the intensity, position and number of the SPV response bands are different obviously. The difference of the SPV response bands is mainly attributed to the different structures of the complexes and the different coordination environment of Mn（ll） in the two complexes. This paper discusses the action of hydrogen bonds in the construction of the supramolecule and the change on the surface photovoltage of complex in different coordination environment.     

New Palladium-Imidazole and Imidazoline Complexes:Structures and Reactivity in Coupling Reaction

1 Results We have recently reported the Mizoroki-Heck reaction catalyzed by PdCl2 and imidazole ligands[1]. During the course of our study of palladium imidazole complex,we disclosed the synthesis of trans-Pd(Ln)2Cl2 by the reaction of PdCl2 with Ln (where L1=2-phenylimidazole,L2=2-phenylimidazole) in a 1∶2 molar ratio.The single crystals of trans-Pd(L1)2Cl2·2DMF (1a) and trans-Pd(L2)2Cl2 (2a) were obtained by following slow evaporation of DMF as a solvent. The single crystal of trans-Pd(L2)2Cl2 (2b) was obtained by slow diffusion of toluene into the DMF solution of complexes,Pd(L1)2Cl2 (1b) was obtained in powder by this way. The compositions of isolated complexes have been determined by elemental analyses. The molecular structures of complex 1a,2a and 2b have been characterized by single crystal X-ray analysis (Fig.1). To compare their catalytic efficiency,the coupling reactions between 4-bromotoluene and tere-butylacrylate using isolated complexes were carried out. In the present of 0.1 mol% palladium complex 1a and 1b,the coupling product were obtained with a yield of 96% after 24 hours and 97% after 12 hours,respectively. The behaviors of obtained complexes in solution based on 1H NMR analysis will be also discussed in the symposium.     

Modulation of active Cr(III) complexes by bath preparation to adjust Cr(III) electrodeposition

The preparation process of the Cr(III) bath was studied based on a perspective of accelerating the formation of active Cr(III) complexes. The results of ultraviolet-visible absorption spectroscopy (UV-Vis) and electrodeposition showed that active Cr(III) complexes in the bath prepared at room temperature in several days were rare for depositing chromium. The increase of heating temperature, time, and pH value during the bath preparation promoted the formation of active Cr(III) complexes. The chromium deposition rate increased with the concentration of active Cr(III) complexes increasing. Increasing the heating temperature from 60 to 96℃, the chromium deposition rate increased from 0.40 to 0.71 μm/min. When the concentration of active Cr(III) complexes increased, the grain size of Cr coatings increased, and the carbon content of the coating decreased. It is deduced that Cr(H₂O)₄(OH)L2+ (L is an organic ligand, and its valence is omitted) is a primary active Cr(III) complex.     

Magnetic properties of heteropolyoxometalates

The progress of the study on the magnetic properties of heteropolyoxometalates during the late decade is reviewed. Some anions of heteropolyoxometalates containing magnetic atoms, such as [M4(H2O)4(PW9O34)2]10- and[M4(H2O)4(P2W15O56)2]16-[M = Co(Ⅱ), Zn( Ⅱ ), Cu( Ⅱ ), Mn(Ⅱ ), Ni(Ⅱ)], and [GaW9O37M3(H2O)3]n-[M = Fe(Ⅲ), Cu(Ⅱ), Co(Ⅱ)] showed ferromagnetic and antiferromagnetic properties. The combination of heteropoly anions and organic π-donor of TTF+ (te-trathiofulvalene cation) results in a variety of magnetic properties. Furthermore, there is an interaction between the inorganic and organic components. The electrocrystallization technique can prepare the organic-inorganic salts of this kind, which will become the new member of molecular magnetic materials. Heteropoly blue is a kind of the mixed-valence complexes and its reduction electrons can be delocalized over anionic framework. The further study on the magnetic properties of heteropolyoxometalates will provide important information for the design of molecular materials.     

Study the effects of divalent metallic ions on the combination of DNA and histones with fluorescence anisotropy assays

The effects of divalent ions(Mn2 ,Mg2 ,Ca2 ) on the interaction between DNA and histone are studied using a fluorescence anisotropy assay. Fluorescence anisotropies of DNA and DNA-histone in the presence of divalent ions(Mn2 ,Mg2 ,Ca2 ) are measured. The results indicate that histone reduces the fluorescence anisotropy of lambda DNA while the divalent ions(Mn2 ,Mg2 ,Ca2 ) significantly enhance the fluorescence anisotropy. Compared to the case of DNA incubated with histone alone,there are more histones binding to DNA when divalent ion,histone and DNA are incubated together. We also find that Mn2 makes the DNA-histone complexes more condensed than the other ions do.     

Palladium(Ⅱ) and Platinum(Ⅱ) Compounds Derived From Potentially Terdentate Ligands

1Introduction Transition metalcomplexes derived from potentially terdentate ligands have attracted great interest in the late years. Among all the examples described so far, those containing palladium(Ⅱ) or platinum(Ⅱ) and ligands holding three heteroatoms with different donor abilities are particularly relevant. In compounds of this kind, the potential hemilability[1] of one of the terminal σ(M-donor atom) bonds, plays an important role in the view of their applications in homogeneous catalysis[2]. On the other hand, it is well-known that in dimetallic complexes the presence of two different metals in a close vicinity may influence their mutual cooperation in a wide variety of processes[3]. Besides that, some examples of the utility of chiral palladium( Ⅱ ) as well as platinum( Ⅱ ) complexes as precursors for organic and/or organometallic synthesis, as chiral recognitors or discriminators, or even in Bio-Medicine have also been reported[4- 6]. However, chiral heterodimetallic compounds holding ferrocenyl units and potentially terdentate ligands are scarce.     

Electrooxidation of Mn(Ⅱ) on Pb-Sb-As Electrode in Sulfuric Acid

The electrooxidation of Mn(Ⅱ) on Pb-Sb-As alloy electrode in sulfuric acid has been investigated.In order to make the two steps of indirect electrosynthesis of benzaldehyde carried out in the same sulfuric acid concentration and also obtain high current efficiency of Mn(Ⅱ) to Mn(Ⅲ) and high yield of Mn(Ⅲ) oxidizing toluene to benzaldehyde in the mean time,the electrooxidation of Mn(Ⅱ) in 60% H2SO4 has been studied.Experimental results show that high current efficiency of Mn(Ⅲ) (about 75%) is obtained in 60%H2SO4 at 60℃.The reason affecting the current efficiency of Mn(Ⅲ) is discussed,and it is the coordination of sulfuric acid concentration and electrolytic temperature.The law is found that it is suitable for electrolysis at low temperature when sulfuric acid concentration is low and at high temperature when sulfuric acid concentration is high.     

Preparation and electrochemical performance of double perovskite La_2CoMnO_6 nanofibers

Through electrospinning,La_2Co Mn O_6 nanofibers were prepared from a polyvinylpyrrolidone/lanthanum nitrate–cobalt acetate–manganese acetate(PVP/LCM)precursor and were used as electrode materials.The morphologies and structures of the samples were characterized by field-emission scanning electron microscopy(FE-SEM),transmission electron microscopy(TEM),X-ray diffraction(XRD),and Brunauer-Emmett-Teller(BET)specific surface area analysis.The results show that the prepared La_2Co Mn O_6 nanofibers are stable,one-dimensional structures formed from interconnected La_2Co Mn O_(6 )nanoparticles with a diamond-like crystal structure.The specific surface area of the fibers is 79.407 m~2·g~(-1).Electrochemical performance tests with a three-electrode system reveal the specific capacitance of the La_2Co Mn O_6 nanofibers as 109.7 F·g~(-1) at a current density of 0.5 A·g~(-1).After 1000 charge-discharge cycles at a current density of 1 A·g~(-1),the specific capacitance maintains 90.9%of its initial value,demonstrating a promising performance of the constraint capacitance and good cyclic stability.     

ZrO_2-supported α-MnO_2:Improving low-temperature activity and stability for catalytic oxidation of methane

The single phaseα-Mn O_2and in-situ supportedα-Mn O_2/Zr O_2with different ratios of Mn/Zr were synthesized by one-pot hydrothermal method.They showed superior activity for catalytic oxidation of methane and even better than that of 1%Pt/Al_2O_3.The T_(50)of Mn O_2/Zr O_2catalysts with different ratios of Mn/Zr were located in the range of 315–335°C at a WHSV of 90 L g~(-1)h~(-1),whereas that of Pt/Al_2O_3was 380°C.After sulfur ageing,the Mn O_2/Zr O_2catalysts with Mn/Zr ratio of 2:1(2Mn O_2/1Zr O_2)and 1:1(1Mn O_2/1Zr O_2)exhibited satisfying sulfur resistance in comparison to the pure Mn O_2.The 2Mn O_2/1Zr O_2catalyst also showed acceptable catalytic stability,and the addition of 10 vol%CO_2had no obvious negative effect on its stability,whereas the addition of2.6 vol%H_2O caused slight but reversible decreasing methane oxidative activity.     

偶氮苯水杨醛Schiff碱及金属配合物的合成与抗菌活性

以水杨醛与苯胺为原料合成偶氮苯水杨醛,并进一步与邻氨基苯酚反应生成了相应的Schiff碱,Schiff碱再与锌(Ⅱ)、锰(Ⅱ)、铁(Ⅱ)三种金属离子络合得到三种金属配合物;采用元素分析、电导率测定、紫外光谱和红外拉曼光谱对Schiff碱及其金属配合物的结构进行表征.结果表明:合成的偶氮苯水杨醛缩邻氨基苯酚配体的结构与理论结构相符,且分别与锌(Ⅱ)、锰(Ⅱ)、铁(Ⅱ)离子配位形成了稳定的金属配合物.对配体及其配合物进行了抗菌活性测试,结果表明配合物的抗菌活性强于Schiff碱配体.     

三(2-甲基苯并咪唑)-锰配合物的合成、表征及对催化H2O2岐化反应活性的增强作用

在乙醇溶剂中,通过Mn(Ⅱ)盐与N,N,N-三(2-甲基苯并咪唑)胺(NTB)反应合成了[Mn(NTB)(Im)]Cl2、[Mn2(NTB)2(H2NCONH2)]Cl4*3H2O、[Mn(NTB)(NO3)](NO3)*3H2O和[Mn(NTB)(HO-phen-OH)]Cl2 4种新配合物,并运用元素分析、摩尔电导、红外光谱和紫外光谱进行了表征.研究了配合物对H2O2岐化反应的催化活性,以及对过氧化氢模拟酶[Fe(NTB)Cl2]Cl*3H2O对H2O2岐化反应活性的影响.实验表明,所合成的锰配合物具有明显的活性增强作用.     

杂环息夫碱及其金属配合物的合成与表征

本文报道了通过水杨醛、香草醛分别与2-氨基-5-偶氮苯吡啶缩合而成新的双齿(N,O或N,N′)杂环息夫碱。将这两种息夫碱作为配体分别与过渡金属盐作用合成了两个系列10种杂环息夫碱配合物M(L_Ⅰ)_2,M(L_Ⅱ)_2Cl_2[其中L_Ⅰ=2-(2′-羟基)苯甲亚胺-5-偶氮苯吡啶;L_Ⅱ=2-(4′-羟基-3’-甲氧基)苯甲亚胺-5-偶氮苯吡啶],并利用元素分析、电导、熔点、磁化率法测定,红外光谱、紫外-可见光谱、热分析等手段进行了表征。基于以上研究推测出配合物可能的空间结构。     

水杨醛缩甘氨酸Schiff碱,2-氨基吡啶或甲醇混配 Cu(Ⅱ),Zn(Ⅱ),Ni(Ⅱ)金属配合物的电化学合成及表征

采用金属Cu,Zn,Ni为"牺牲"阳极,在无隔膜电解槽和含配体水杨醛缩甘氨酸Schiff碱、2-氨基吡啶的甲醇溶液中首次电解合成了Cu(Ⅱ),Zn(Ⅱ),Ni(Ⅱ)配合物.利用元素分析、质谱、核磁、红外光谱、紫外光谱、热分析对配体和配合物进行了表征,确定了配合物的化学组成为ML.L.′nH2O[L=C9H7NO3,(M=Cu(Ⅱ),L′=CH3OH,n=0;M=Zn(Ⅱ)、Ni(Ⅱ),L′=2-氨基吡啶n=1)].电合成Zn(Ⅱ)、Ni(Ⅱ)配合物的电化学效率Ef接近0.5 mol.F-1,电极反应为2电子反应,电合成Cu(Ⅱ)配合物的电化学效率Ef接近1.0 mol.F-1,电极反应为1电子反应,Schiff碱配体均以三齿进行配位.Cu(Ⅱ)配合物中Cu(Ⅱ)(L)L′/Cu(I)(L)L′电对的可逆半波电位Er1/2为-1.225 V(vs SCE).     

基于{Cr（OH）6Mo6O18）^3-多酸阴离子为配体的过渡金属离子配合物的合成及结构表征

以β-Anderson型{Cr（OH）6Mo6O18}^3-多酸阴离子为配体,质子化的4,4’-bpy为模板,利用电荷平衡阳离子,在水热条件下,合成了三种过渡金属Mn（Ⅱ）、Co（^3-）和Ni（^3-）的配合物：[4,4’-bpyH2]2[-Mn{Cr（OH）6Mo6O18}2]1、[4,4＇-bpyH][-Co（H2O）2{Cr（OH）6Mo6O18）]·4H2O2和[4,4’-bpyH][-Ni（H2O）2{Cr（OH）6Mo6O18}]·4H2O3．通过元素分析、单晶X射线分析、红外表征、热重分析和X射线粉末衍射等技术确定了化合物的组成和结构．在配合物1中,{Cr（OH）eMo6O18}^3-多酸阴离子作为六齿配体,Mn（Ⅱ）采用八面体配位方式,形成一维带状结构．配合物2和3互为异质同构体,{Cr（OH）6Mo6O18}^3-多酸阴离子作为四齿配体,Co（Ⅱ）或Ni（Ⅱ）采用八面体配位方式,形成二维层状结构,[4,4’-bpyH]＋填充在层间．     

5-氟尿嘧啶、邻菲罗啉、过渡金属离子三元配合物的合成与表征

5-氟尿嘧啶(5-FU)、邻菲罗啉与过渡金属锰(Ⅱ)、铁(Ⅲ)、钴(Ⅱ)、镍(Ⅱ)、铜(Ⅱ)、锌(Ⅱ)在水和乙醇的混合溶剂中搅拌回流,合成了一系列配位化合物,通过可见-紫外光谱,红外光谱,荧光光谱等手段对配合物进行了表征.     

系列Mn(Ⅱ)配合物的光电性能研究

采用水热方法合成了2个Mn(Ⅱ)配合物[Mn(pzdc)( H2O)2]n(1)(H2pzdc=3,5-吡唑二羧酸),[Mn(phen)(pdc)(H2O)2] · H2O(2)(H2pdc=2,5-吡啶二羧酸),通过单晶X-射线衍射确定了配合物的晶体结构.结构分析表明,配合物1属于单斜晶系,P21/c空间群,在晶体中,中心金属Mn(Ⅱ)离子为6配位,是以3,5-吡唑二羧酸为桥连接起来的具有1D无限结构的配位聚合物;配合物2属于三斜晶系,P-1空间群,在晶体中,中心金属Mn(Ⅱ)离子为6配位,是单核结构,氢键将其连接成具有2D结构的配位超分子.在室温下对配合物的IR和UV-Vis-NIR吸收光谱进行了测定和分析指认.而且利用表面光电压光谱研究了配合物的表面光伏性能.结果表明,配合物1和2在300～500 nm范围内呈现出正的光伏响应.并且随着Mn(Ⅱ)离子配位环境不同,光伏响应带数目和强度也明显不同.     

铜的一维配聚物和双(μ-硫)桥联二聚物的磁性研究

制备了铜的氯桥联的一维聚合物{[(CuClL'][Cl]}n和二聚体[CuLCl2]2, 测试了这两种化合物在1.8 ～ 300 K 范围内的变温磁化率. 理论拟合表明:通过氯原子或硫原子的传递作用,在铜离子之间存在弱的反铁磁偶合.     

L-苏糖酸与Mn(Ⅱ)、Hg(Ⅱ)的配位性能研究

本文在前文的基础上，研究了Ｌ－苏糖酸与Ｍｎ（Ⅱ）、Ｈｇ（Ⅱ）的配位性质，测定了所形成的二元配合物的稳定常数，Ｍｎ（Ⅱ），５．２２（１２０）；Ｈｇ（Ⅱ），３．６０（１１０），６．１１（１２０），对其配位性质与同族元素进行了比较研究．