New Metal Chelates with Sterically Hindered Azo Ligands: Synthesis and Physicochemical Properties

Metal chelates based on 3,5-di-(tert-butyl)-2-hydroxyazobenzene are synthesized and their physicochemical properties were studied. Four alternative structures and isomeric transformations between these structures were suggested on the basis of NMR data, electric dipole and magnetic moments, X-ray diffraction and quantum-chemical data. The change in stereochemistry of a complex through introduction of tert-butyl substituents was found to give unusual (for metal chelates with azo ligands (MN₂O₂)) dome-shaped isomers with the trans-planar coordination core at a vertex or with a distorted cis-structure.__________Translated from Koordinatsionnaya Khimiya, Vol. 31, No. 8, 2005, pp. 563–571.Original Russian Text Copyright © 2005 by Kogan, Lyubchenko, Shcherbakov, Ionov, Tkachev, Shilov, Aldoshin.     

Synthesis,Structure, and Reactivity of Metal Complexes with Alkoxysilylmethyl Ligands

The synthesis and properties of the new metal complexes 1 , 6 – 12 with alkoxysilylmethy substituents (RO–SiR′₂–CH₂–ML_n) is described. The complexes 14 , 15 and 18 with a chloromethylsiloxy ligand were also prepared. These molecules should serve as starting compounds for the synthesis of metallasilaoxetanes. Several reactions which should lead to these new metallacycles have been performed, but it was never possible to isolate them or to proof their existence spectroscopically. However, chloride abstraction from (C₅H₅)₂Ti(Cl)CH₂Si(CH₃)₂O^tBu ( 7 ) by silver cations led to the activation of the Si–O–R group. This indicates an interaction of the oxygen atom with the metal atom, but there was no proof for the intermediate formation of a four membered metallacycle.     

Jones-Dole Equation B Coefficients for Metal Chelates and Selected Ligands

Abstract

The B coefficient of the Jones-Dole equation is required to determine the size of the solvation sphere of a molecule in solution. Those obtained for metal chelates and selected ligands are presented.     

离子对型[O,N,N]三齿席夫碱镱氯化物的合成及其晶体结构

无水YbCl3和席夫碱[HL=3,5-(t-Bu)2-2-HOC6H2CH=N-8-C9H6N]锂盐按1∶1物质的量比在THF中反应,得到离子对席夫碱镱氯化物YbLCl3Li(DME)3(1).标题配合物1经元素分析、IR光谱和X射线衍射结构表征.配合物1属单斜晶系,P21/n空间群,晶胞参数:a=1.4855(16)nm,b=1.3696(13)nm,c=2.1816(2)nm,α=90.00°,β=98.217(3)°,γ=90.00°,V=4.3748(8)nm3,Z=4,F(000)=1868,Mr=916.17,Dc=1.397 g.cm-3,μ=2.364 mm-1,R1=0.0855,wR2=0.1863.     

Synthesis,Characterization, and Properties of Tetraphenylethylene-Based Tetrakis-NHC Ligands and Their Metal Complexes

The development of highly emissive dinuclear Ag^I or Au^I complexes [M₂L](PF₆)₂ (L= 2 a , 2 b ; M=Ag, Au) derived from tetraphenylethylene (TPE)-based tetrabenzimidazolin-2-ylidene ligands is reported. The new complexes exhibit a remarkable fluorescence enhancement compared to their parent benzimidazolium salts. The quantum yield (Φ_F) value for salt H₄- 2 a (PF₆)₄ in dilute solution (c=10⁻⁵ m ) was found to be less than 1 %, whereas its metal complexes show Φ_F values up to 55 % at similar solution concentration. This observation can be attributed to the rigidification of the TPE skeleton upon metalation resulting in a restriction of the intramolecular rotation of the phenyl groups. Functionalization of the complexes [M₂ 2 b ](PF₆)₂ (M=Ag, Au) with terminal coumarin groups and subsequent photoirradiation yielded the complexes [M₂ 3 b ](PF₆)₂ (M=Ag, Au) bearing a new type of ligand with an unaffected TPE moiety.     

Simultaneous Thermogravimetry and Differential Thermal Analysis of Non-Oxo Vanadium(IV) Chelates with Tridentate Diacidic Ligands

The TG and DTA curves of non-oxo vanadium(IV) chelates with tridentate diacidic li-gands were recorded. The ligands contain the donor set O^∩N^∩O(S) and belong in the groups of dihydroxy azo- or azomethine compounds, and of β-dicarbonyl (salicyl) benzoyl (salicyl)hy-drazones. The onset temperatures, the mass defects and the reaction rates were calculated.     

偶氮金属螯合物的合成及其光学和热学性质

偶氮金属螯合物的合成及其光学和热学性质;噻唑基偶氮金属螯合物;光学性质     

Synthesis,Structure and Characterization of Schiff Base Metal Complexes and Their Electrochemical Properties of Thionyl Chloride Reduction

A symmetric tetradentate Schiff base ligand bis(3‐methoxysalicylidene)‐o‐phenylenediamine (H₂L) was prepared. A series of transition metal complexes with this Schiff base ligand have been synthesized and structurally characterized by IR and elemental analysis. The catalysis for reduction of thionyl chloride was studied by means of constant resistance discharge. The result shows that [Mn(III)LCl(H₂O)]CH₃OH and [Co(II)HLCl(H₂O)] have a good catalytic activity for the reduction of thionyl chloride, which improves the cell voltage, the rate of discharge, and the lifetime of Li/SOCl₂ batteries.     

多金属氧酸盐修饰的过渡金属配合物的催化效果和电化学行为

基于水热技术,合成了多金属氧酸盐修饰的2种新的过渡金属配合物[Cu（dmbipy）₂（SiW₁₂O₄₀）][Cu（dmbipy）（H₂O）₃]·3H₂O（1）和{（Hdmphen）₂[Ag₂（dmphen）₂（SiW₁₂O₄₀）]}_n（2）（dmbipy=4,4＇-二甲基-2,2＇-联吡啶, dmphen=2,9-二甲基-1,10-菲咯啉）。配合物1的最小不对称单元包含2种不同的Cu（Ⅱ）单元,其中Cu（Ⅱ）离子都采用了五配位的模式,并且水分子也参与了配位。氢键将不同的Cu（Ⅱ）单元连接形成了一维链,并延伸至二维层。在配合物2中,多金属氧酸盐连接Ag（Ⅱ）离子形成一维链。氢键和π…π堆积作用将一维链拓展成了二维层。     

多金属氧酸盐修饰的过渡金属配合物的催化效果和电化学行为

基于水热技术,合成了多金属氧酸盐修饰的2种新的过渡金属配合物[Cu（dmbipy）²（SiW¹²O⁴⁰）][Cu（dmbipy）（H₂O）₃]·3H₂O（1）和{（Hdmphen）²[Ag₂（dmphen）²（SiW¹²O⁴⁰）]}_n（2）（dmbipy=4,4’-二甲基-2,2’-联吡啶,dmphen=2,9-二甲基-1,10-菲咯啉）。配合物1的最小不对称单元包含2种不同的Cu（Ⅱ）单元,其中Cu（Ⅱ）离子都采用了五配位的模式,并且水分子也参与了配位。氢键将不同的Cu（Ⅱ）单元连接形成了一维链,并延伸至二维层。在配合物2中,多金属氧酸盐连接Ag（Ⅱ）离子形成一维链。氢键和π…π堆积作用将一维链拓展成了二维层。     

Synthesis,Structure, and Thermochemical Properties of Alkali Metal Uranoborates

Compounds of the composition ABUO5 (A are alkali metals) were synthesized. Their structure and thermal decomposition were studied, standard enthalpies of formation were determined, and enthalpies of solid-phase reactions of their synthesis from oxides and by ion-exchange reactions were calculated.     

Synthesis, Crystal Structure and Electrochemical Properties of 2-Chlorobenzaldehyde Thiosemicarbazone

Recently,tremend0useffortshavebeendevotedtosynthesisof0rgan0metalliccomp0undswithlargesecondorder0pticaln0nlinearities."2'3H0wever,fewofthemcanbeusedasapplicablematerials,owingtotheintensecolorofmosttransitionmetalcomplexes.Andwef0undthatthatpalecolormetalcomplexesderivedfromthiosemicarbazonemightbethepossiblewaytoobtainthenonlinearopticalcompoundwhichcouldbeusedasaPplicablematerials.InthispaPer,2-chlorobenzaldehydethiosemicarbazoneligandhasbeendesignedandsynthesized,thecomplexofcadmiumbromid…     

Schiff碱双核Mn配合物的合成、结构和性能研究

Five manganese complexes of Schiff base were synthesized： [Mn^Ⅳ，Ⅳ(μ-O)(Salen)]₂·DMF·H₂O (1)， [Mn^Ⅳ，Ⅳ(μ-O)(5-BrSalen)]₂·DMF·0.5H₂O (2)， {Mn^Ⅳ，Ⅳ(μ-O)[Sal(1，2-pn)]}₂·H₂O (3)， {Mn^Ⅳ，Ⅳ(μ-O)[5-Br-Sal(1，2-pn)]}₂·H₂O (4)， {Mn^Ⅳ，Ⅳ(μ-O)[5-CH₃-Sal(1，2-pn)]}₂·2H₂O (5)， and were characterized by element analysis， IR and UV-Vis spectra. The results of cyclic voltammogram show that Schiff base ligands can drop the potential of manganese and steady high oxide state of manganese. The magnetic properties of 1 and 3 have also been studied. The results show that there is a weak ferromagnetically coupling of Mn^Ⅳ₂ pair at room and low temperature， and the interactions of complex 3 are weaker than complex 1.     

Synthesis,Structure and Electrochemical Properties of Acetamide- and Caprolactam-Containing Silicon Catecholates

Hexacoordinated heteroligand silicon catecholates, although being prospective as easily soluble compounds with high hydrolytic stability and diverse redox properties, have been insufficiently studied. The transesterification of 1-(trimethoxysilylmethyl)-2-oxohexahydroaze or N-methyl-N-(trimethoxysilylmethyl)acetamide by two equivalents of catechol derivatives in the presence of dicyclohexylamine afforded a series of target compounds in good yield. The complexes were characterized using elemental analysis, FTIR, ¹H, ¹³C and ²⁹Si NMR spectra, X-ray crystallography and cyclic voltammetry. X-ray diffraction confirmed that the silicon atom possesses the octahedral geometry of the SiCO₅ polyhedron that remains unchanged in solution as it follows from ²⁹Si NMR data. The compounds demonstrated up to three oxidation waves; and the reduction profile strongly depended on the nature of the substituents on a catecholate anion.     

Synthesis,Structure, Magnetic and Electrochemical Properties of a Dinuclear Copper Complex

A material for both magnetic coupling and electrocatalytic hydrogen evolution based on the copper complex, [(L)₂Cu₂] is formed by the reaction of CuCl₂ · 2H₂O with the tetradentate ligand 6‐(3‐aminomethylpropanol)‐2‐tert‐buty‐4‐methylphenol (H₂L), which is prepared by reaction of 2‐tert‐butyl‐4‐methylphenol, 3‐amino‐1‐propanol, and formaldehyde. Structural studies show that in the solid state complex 1 exhibits strong antiferromagnetic exchange interaction between copper(II) ions mediated by oxygen‐bridges. In liquid, 1 becomes a monomer, and can electrocatalyze hydrogen generation both from acetic acid with a turnover frequency (TOF) of 101.70 mol of hydrogen per mole of catalyst per hour at an overpotential (OP) of 941.6 mV (in DMF), and a natural buffer with a TOF of 650 mol of hydrogen per mole of catalyst per hour at an OP of 836.7 mV.     

基于吡啶二羧酸配体的稀土配合物的合成、结构及性质

以2,6-二甲基吡啶-3,5-二羧酸（H₂L₁）为主配体,1,10-菲咯啉（L₂）为辅配体,分别与五水合硝酸镝、六水合硝酸铽及六水合硝酸铕通过水热法合成[Dy₂（L₁）₃（L₂）₂]_n（1）、{[Tb₂（L₁）₃（L₂）₂]·5H₂O}_n（2）和{[Eu₂（L₁）₃（L₂）₂]·5H₂O}_n（3）三种配合物。通过单晶X射线衍射、红外光谱、荧光光谱和热重分析对其结构进行了表征与性质研究。结果表明,配合物1~3均以稀土离子为金属节点连接配体L₁^2-和L₂,形成无限延伸的一维链状结构。     

含共轭三烯吡啶配体的配位聚合物的合成、结构及荧光性质

将1,6-双（4-吡啶基）-1,3,5-己三烯（bphte）和镉盐分别与2种羧酸配体（2,5-二呋喃二甲酸（2,5-H₂FDC）及1,3,5-均苯三甲酸（1,3,5-H₃BTC））进行溶剂热反应,得到2个配位聚合物：[Cd （2,5-FDC）（bphte）（H₂O）]_n （1）和[Cd （1,3,5-HBTC）（bphte）]_n （2）。对配合物1和2分别进行了元素分析、红外光谱、单晶X射线衍射、粉末X射线衍射和热重分析表征。配位聚合物1具有spl拓扑结构的三维互穿超分子框架,而配合物2是由bphte配体交叉连接一维链[Cd₂（1,3,5-HBTC）₂]_n形成的三维结构。配合物1和2在固态时表现出不同的荧光性质。配合物2遇到水溶液中Fe³⁺会发生荧光猝灭,因此以其作为荧光探针对水溶液中Fe³⁺进行了选择性荧光检测,它对Fe³⁺的检测限可达到0.013 μmol·L^-1。这种荧光猝灭过程可归因于Fe³⁺离子的吸收带与配合物2的激发带之间存在部分重叠。     

四苯基[b,f,j,n][1,5,9,13]四氮杂环十六碳炔镍轴向氮碱加合物的合成、结构和性质研究

合成了3个四苯基[b,f,j,n][1,5,9,13]四氮杂环十六碳炔镍轴向氮碱加合物[Ni(TAAB)(L)_2](BF_4)_2(L为吡啶、咪唑、DMF)以及4,4′-联吡啶桥联配合物[Ni(TAAB)(μ-4,4′-bipy)]。[(ClO_4)_2·H_2O]_((??))。用元素分析、IR和热分析对标题化合物作了表征。双吡啶加合物的晶体结构显示,TAAB大环呈马鞍形结构,轴向配位的吡啶环平面相互垂直,轴向的2个Ni—N键长明显比赤道平面的4个Ni—N键长大,形成拉长的配位八面体。4,4′-联吡啶配合物的变温磁化率表明,镍(Ⅱ)离子间存在反铁磁性磁交换相互作用。