Synthesis and crystal structure of bis(m-hydroxybenzoato(1-))bis(benzimidazole) copper(II) dihydrate

The crystal structure of the title complex was determined by single-crystal X-ray diffraction methods. The unit cell contains two independent molecules, A and B. B is a mononuclear Cu(II) complex with square-planar coordination geometry formed by two benzimidazole molecules and two hydroxylbenzoate anions. A is a dimer of B, formed by bridging hydroxybenzoate, and copper assumes square-pyramidal geometry. Aromatic π–π stacking is observed between parallel benzimidazole rings of neighboring A molecules. IR spectra of the compound are assigned in line with the crystal structure.     

Solvothermal Synthesis and Crystal Structure of a 1D Helical-chain Cobalt（II） Complex Containing （Quinolin-8-yloxy）acetate

The cobalt(II) complex with (quinolin-8-yloxy)acetate, [CoCl(C11H8NO3)]n (1), has been prepared via the solvothermal method and characterized by IR, elemental analysis, UV- Vis diffuse-reflection spectra and single-crystal X-ray diffraction analysis. Complex 1 is a novel carboxylate-bridged one-dimensional helical cobalt(II) polymer, and the Co(II) centre exhibits an approximately square pyramidal CoClNO3 coordination geometry. It crystallizes in monoclinic, space group P21/n, with a = 9.1594(10), b = 6.8864(7), c = 17.290(2) , β = 102.629(3)o, C11H8ClCoNO3, Mr = 296.56, V = 1064.2(2) 3, Z = 4, Dc = 1.851 g/cm3, F(000) = 596, μ = 1.856 mm-1, the final R = 0.0308 and wR = 0.0807. Interestingly, the chain complexes are assembled to form two-dimensional networks through intermolecular face-to-face π-π stacking interactions with the centroid-to-centroid distance of 3.559(1)  and the dihedral angle of 8.4(1)° between the aromatic rings.     

5-(4-硝基苯偶氮)-8-(4-甲苯磺酰氨基)-喹啉的合成及在钴的测定中的应用研究

首次合成了5-(4-硝基苯偶氮)-8-(4-甲苯磺酰氨基)-喹啉,测量了其酸离解常数。在非离子型表面活性剂存在下,试剂与钴(Ⅱ)在pH9.0～11.2范围内形成配合物,ε_(645)=1.01×10~5L·mol~(-1)cm~(-1),在H_2o_2作用下,于λ_((?)m)/λ_((?)x)=420nm/345nm产生强荧光,建立了一个操作简便快速、灵敏度高、选择性好的荧光分析新方法,线性范围2～32ppb,检测极限0.1ngCo(Ⅱ)/ml,用以测量了维生素B_(12)及生物样品中的痕量钴(Ⅱ)。探讨了H_2O_2对荧光增敏的机理。     

Synthesis and characterization of cerium,thorium, and uranyl complexes with ( E )-4-(4-methoxyphenoxy)-4- oxobut-2-enoic acid

(E)-4-(4-Methoxyphenoxy)-4-oxobut-2-enoic acid and its Ce(IV), Th(IV), and UO₂(II) complexes were synthesized and characterized by MS, elemental analysis, IR, UV, TG-DTA, and NMR. The complexes have composition [CeL₂(OH)₂ · 2H₂O] · H₂O, [ThL₂(OH)₂ · 2H₂O] · H₂O, and [UO₂L₂ · 2H₂O] · H₂O. Molar conductance data confirm that the three complexes are nonelectrolytes. The IR and NMR results show that the carboxylates coordinate to the metal ions bidentate, and the ester carboxylic groups do not take part in coordination. Luminescence spectra of the ligand and complexes in DMSO at room temperature were also studied showing strong luminescence of the metal ions.     

4-(N-乙基-3-甲基苯胺基）丁酸甲酯的合成

以γ-丁内酯为起始原料,经开环氯化和醇解反应合成4-氯丁酸甲酯（2）; 2与N-乙基间甲苯胺经亲核取代反应合成了4-(N-乙基-3-甲基苯胺基）丁酸甲酯,纯度97.5%,总收率75.3%,其结构经¹H NMR确证。     

A series of 2D lanthanide (III) coordination polymers constructed from 2-(pyridin-3-yl)-1H-imidazole-4,5-dicarboxylate

Reactions of 2-(pyridine-3-yl)-1H-4,5-imidazoledicarboxylic acid (H₃PyIDC) with a series of Ln(III) ions affords ten coordination polymers, namely, {[Ln(H₂PyIDC)(HPyIDC)(H₂O)₂]·H₂O}_n [Ln=Nd (1), Sm (2), Eu (3) and Gd (4)], {[Ln(HPyIDC)(H₂O)₃]·(H₂PyIDC)·H₂O}_n [Ln=Gd (5), Tb (6), Dy (7), Ho (8) and Er (9)], and {[Y₂(HPyIDC)₂(H₂O)₅]·(bpy)·(NO₃)₂·3H₂O}_n (10) (bpy=4,4′-bipyridine). They exhibit three types of networks: complexes 1-4 are isomorphous coordination networks containing neutral 2D metal-organic layers, while complexes 5-9 are isomorphous, which consist of cationic metal-organic layers and anionic organic layers, and complex 10 is a 2D network built up from 4-connected HPyIDC²⁻ anion and 4-connected Y(III) ions. In addition, thermogravimetric analyses and solid-state luminescent properties of the selected complexes are investigated. They exhibit intense, characteristic emissions in the visible region at room temperature.     

Synthesis and Crystal Structure of a New Copper(II) Complex with 4-Cyanobenzoic Acid

1 INTRODUCTION Exploration on the syntheses and properties of car- boxylate complexes, especially aromatic carboxylate complexes, has always been a fascinating and chal- lenging research field for decades either in coor- dination chemistry or in functional materials[1, 2]. Cy- anobenzoic acid (Hcba) possessing two functional coordination groups should display structural diver- sities on the formation of complexes[3～15]. In particu- lar, the copper(II) carboxylate complexes bearing spe- …     

A twofold interpenetrated 3-D Cu(II) coordination polymer based on 5-(pyridin-4-yl)isophthalic acid: synthesis,crystal structure,and magnetic properties

A new copper(II) coordination polymer, [Cu(PIA)·2H₂O]_n (1) [H₂PIA = 5-(pyridin-4-yl)isophthalic acid], has been synthesized and characterized by elemental analysis, IR spectroscopy, TGA, powder, and single-crystal X-ray diffraction. Structural analysis shows that each PIA^2? in 1 bridges three Cu(II) ions, and likewise each Cu(II) ion connects to three PIA^2? ligands, giving a 3-D framework with utp topology and left-/right-handed helical channels. Interestingly, two such identical frameworks interlock with each other to generate a twofold interpenetrated structure that is stabilized by hydrogen bonding and π–π interactions. In addition, the thermal stability and the magnetic properties of 1 have been investigated.     

Synthesis, crystal structures and photoluminescent properties of lanthanide supramolecular complexes with 4-oxo-1(4H)-quinolineacetate

Five new lanthanide supramolecular complexes, namely, [Sm(oqa)₂(H₂O)₄]₂ (ClO₄)₂·(bpy)₂ (1), [Ln(oqa)₃]·2H₂O [Ln=Sm(2), Gd(3)] and [Ln(oqa)₂(NO₃)(H₂O)] [Ln=Pr(4), Eu(5)] (oqa=4-oxo-1(4H)-quinolineacetate, bpy=4,4′-bipyridine), have been synthesized under hydrothermal conditions. These complexes exhibit three typical structure features. Complex 1 possesses a dimeric structure, which is further connected together through hydrogen bonds and π-π attractions, forming a 3D supramolecular framework. Compounds 2-3 are isomorphous and contain 1D ring-like chains, which are further interconnected by the oqa ligands into 2D sheet-like structures. 4 and 5 exhibit eight-connected 3D network of 4²⁴·6⁴-bcu topology. The various coordination modes of carboxylate ligands and the selection of the counterions have clearly affected the topological structures. Furthermore, the solid-state luminescent properties of complexes 1, 2 and 5 were investigated at room temperature and they show intense, characteristic emissions in the visible region.     

N-[2-(4-Methoxy-phenyl)-ethyl]-2-(quinolin-8-yloxy)acetamide: a receptor for acid binding

Different hydrates of the receptor, N-[2-(4-methoxy-phenyl)-ethyl]-2-(quinolin-8-yloxy)acetamide (I), and its co-crystals with acetic acid and l(+)α-hydroxy-phenylacetic acid are synthesised and their structures are studied. The acids such as acetic acid, l(+)α-hydroxy-phenylacetic acid quench fluorescence of I. The receptor I shows a fluorescence quenching on interaction with perchloric acid in benzene, whereas in methanol the solution of I results in the generation of a new fluorescence emission at higher wavelengths. The crystal structure of the perchlorate salt is determined to explain the protonation behaviour of the receptor I and the perchlorate salt in methanol leads to fluorescence emission at a place different from that of the parent compound.     

Synthesis,properties, and X-ray crystal structures of two Ag(I) complexes with 2-(pyridin-4-yl)-1H-imidazole-4,5-dicarboxylic acid

Two 1-D and 3-D Ag(I) complexes involving 2-(pyridin-4-yl)-1H-imidazole-4,5-dicarboxylic acid (H₃PIDC) have been characterized by infrared spectrum, elemental analysis, and single-crystal X-ray diffraction. [Ag₂(HPIDC)]_n (1), synthesized under hydrothermal conditions, gave a 3-D framework; [Ag₂(HPIDC)(MBI)]_n (2) (MBI?=?2-methyl-1H-benzo[d]imidazole), with MBI as the second ligand, gave a 1-D zigzag chain and further formed a 3-D supramolecular structure through π···π interactions. The most interesting structural features of these complexes are the presence of C–H···Ag hydrogen bonding interactions and Ag···C weak interactions between the Ag centers and H₃PIDC. Luminescence indicates that 2 has significantly stronger fluorescent emissions than 1 in the solid state at room temperature.     

(R)-2-硫代四氢噻唑-4-羧酸及其酯的合成

L-半胱氨酸盐酸盐与二硫化碳, 氢氧化钠在硝酸铅存在下进行成环反应得到(R)-四氢噻唑-2-硫酮-4-羧酸产率76% , 后者与 醇在硫酸铁水合物催化下反应得到(R)-四氢噻唑-2-硫酮-4-羧酸酯, 产率40～82% .     

配合物{[Co(5-氨基-8-羟基喹啉)_2]·H_2O}_n的合成及结构研究

以4-[(8-羟基-5-喹啉)偶氮]-苯磺酸与氯化钴为原料,采用溶剂热法通过原位反应合成{[Co(5-氨基-8-羟基喹啉)_2]·H_2O}_n,并通过X-射线单晶衍射方法确定了该配合物的晶体结构.结构分析表明:标题配合物属于斜方晶系,Pbcn空间群,晶胞参数a=1.321(2)nm,b=0.811(2)nm,c=1.511(2)nm,α=β=γ=90.00°,V=1.619(3)nm~3,Z=4,R_1=0.0516,w R_2=0.1025.配合物中存在ππ堆积相互作用和氢键作用,将配合物连接形成三维超分子网络结构.     

基于4-(2,4-二羧基苯氧基)邻苯二甲酸配体的锌配位聚合物的合成、结构及其荧光传感性能

基于H₄dpa和bpy(H₄dpa=4-(2,4-二羧基苯氧基)邻苯二甲酸,bpy=4,4''-联吡啶)为配体,在水热条件下设计、合成了金属锌配位聚合物(Zn-CP)[Zn(H₂dpa)(bpy)_1.5]_n (1),并用元素分析、红外光谱、X射线单晶衍射等对其进行了结构表征。在1中相邻Zn²⁺与H₂dpa^2-离子和bpy配位形成的一维双链结构,相邻的一维双链通过氢键作用扩展形成三维超分子网结构。荧光研究表明:1是一种灵敏度高、选择性好、多响应的荧光传感器,可用于农药和硝基爆炸物的检测。有趣的是,2,4,6-三硝基苯(TNP)和嘧霉胺(Pth)对1的荧光发射显示出明显的猝灭效果,而抑霉唑(Ima)对1有荧光增强效果。此外,通过紫外可见吸收光谱、荧光寿命以及X射线光电子能谱探究了1的荧光传感机理。     

(R)-N-乙酰基-四氢噻唑-2-硫酮-4-甲酰TT的合成及其晶体结构

由N-乙酰(R)-四氢噻唑-2-硫酮-4-羧酸在三聚氯氰及三乙胺存在下与四氢噻唑-2-硫酮反应得到标题化合物，[α]^2^0~D +11.18°。用X射线衍射法测得其晶体结构，属单斜晶系，空间群为P2~1/c。晶体学数据：a=0.9959(4)nm，b=1.1469(4)nm，c=1.1108(3)nm，β=92.72(3)°，V=1.2673(8)nm^3，Z=4。分子中两个C=O基，两个C=S基团处于C(1)-N(1)-C(4)及C(6)-N(2)-C(7)键两侧呈反式。用PM3分子轨道方法研究了该化合物的电子结构，电荷和键序分布，得到该化合物前线轨道性质。     

(R)-4-氰基-3-羟基丁酸乙酯的合成

研究了一条新的路线用于他汀类药物的重要中间体(R)-4-氰基-3-羟基丁酸乙酯的合成. 以廉价、易得的L-(－)-苹果酸为起始原料, 经酯化、还原、溴代和氰化四步反应得到目标化合物(R)-4-氰基-3-羟基丁酸乙酯, 合成总收率为56.7%. 所有中间体和最终产物均由ESI-MS, 1H NMR和13C NMR光谱及比旋光度表征并与文献值比较. 该方法原料易得、操作简便、收率良好, 产物容易分离纯化, 是一条适合大规模制备(R)-4-氰基-3-羟基丁酸乙酯的新合成工艺路线.     

7-(对甲酰基苯偶氮)-8-羟基喹啉-5-磺酸的合成及其双波长分光光度法测定镓

7－（对甲酰基苯偶氮）－8－羟基喹啉－5－磺酸是一新显色剂。该试剂在微碱性介质中（pH＝7．5）与镓形成黄色络合物。络合物λmax＝392nm，摩尔吸光系数ε392＝2．24×104L·mol-1·cm-1。同时在500nm呈现负峰，用双峰观波长法测定镓ε392～500＝6．89×104L·mol-1·cm－1，灵敏度是单波长法的三倍多．线性范围0～2．0×10－5mol／L。用拟定的方法测定了掺硅的GaAS材料及岩石中的镓，加入回收率为106％～110％；方法的相对标准偏差小于1．6％。     

基于4-(2，4-二羧基苯氧基)邻苯二甲酸配体的锌配位聚合物的合成、结构及其荧光传感性能

基于H₄dpa和bpy (H₄dpa=4-(2,4-二羧基苯氧基)邻苯二甲酸,bpy=4,4''-联吡啶)为配体,在水热条件下设计、合成了金属锌配位聚合物(Zn-CP)[Zn(H₂dpa)(bpy)_1.5]_n (1),并用元素分析、红外光谱、X射线单晶衍射等对其进行了结构表征。在1中相邻Zn²⁺与H₂dpa^2-离子和bpy配位形成一维双链结构,相邻的一维双链通过氢键作用扩展形成三维超分子网结构。荧光研究表明：1是一种灵敏度高、选择性好、多响应的荧光传感器,可用于农药和硝基爆炸物的检测。有趣的是,2,4,6-三硝基苯(TNP)和嘧霉胺(Pth)对1的荧光发射显示出明显的猝灭效果,而抑霉唑(Ima)对1有荧光增强效果。此外,通过紫外可见吸收光谱、荧光寿命以及X射线光电子能谱探究了1的荧光传感机理。