基于双核{Zn2(COO)4}次级构筑单元的二维发光配位聚合物的晶体结构和对Fe3+的检测

使用H2L配体（H2L=2-（1,3-dioxo-1H-benzo[de]isoquinolin-2（3H）-yl） terephthalic acid）和Zn²⁺通过水热反应,合成了一例基于双核{Zn₂（COO）₄}次级构筑单元的二维发光配位聚合物[Zn₂（L）₂（DMSO）₂（DMF）]（1）（DMSO=二甲亚砜,DMF=N,N-二甲基甲酰胺）。拓扑分析表明1结构中的双核{Zn₂（COO）₄}单元可视为4连接节点,并与作为连接子的L^2-形成（4,4）-网拓扑构型。1表现出对Fe³⁺离子的选择性发光猝灭响应,检测限为2.8 μmol·L^-1。1对Fe³⁺的检测具有良好的抗干扰性,且可通过DMF溶剂洗涤实现再生,可多次循环使用。     

基于双核{Zn2(COO)4}次级构筑单元的二维发光配位聚合物的晶体结构和对Fe3+的检测

使用H₂L配体（H₂L=5-（1,3-dioxo-1H-benzoisoquinolin-2（3H）-yl） isophthalic acid）和Zn²⁺通过水热反应,合成了一例基于双核{Zn₂（COO）₄}次级构筑单元的二维发光配位聚合物[Zn₂（L）₂（DMSO）₂（DMF）]（1）（DMSO=二甲亚砜,DMF=N,N-二甲基甲酰胺）。拓扑分析表明1结构中的双核{Zn₂（COO）₄}单元可视为4连接节点,并与作为连接子的L^2-形成（4,4）-网拓扑构型。1表现出对Fe³⁺离子的选择性发光猝灭响应,检测限为2.8 μmol·L^-1。1对Fe³⁺的检测具有良好的抗干扰性,且可通过DMF溶剂洗涤实现再生,可多次循环使用。     

一例互穿的阴离子型In（Ⅲ）金属有机骨架用于选择性检测水中Fe3+离子

作为一类新型多孔材料,金属有机骨架（MOFs）常被开发作为荧光传感器用来监测水中的污染物,开发稳定且易制备的MOFs材料实现选择性检测有毒的Fe³⁺仍具有较高挑战。本工作中,我们报道一例水稳定的二重穿插In（Ⅲ）基MOF：（NH₂Me₂）[In （fdc）₂]·2H₂O （BUT-205,BUT代表北京工业大学,H₂fdc=呋喃-2,5-二羧酸）。BUT-205的构筑采用生物质衍生配体,其结构通过单晶X射线衍射确立。这个材料可作为高效的水相Fe³⁺离子传感器,具有高的灵敏度和选择性。检测限达到1.3 μmol·L^-1,低于美国环保局规定的饮用水中安全标准（15.7 μmol·L^-1）,并且该传感材料可以回收利用至少4次。     

异核Ln(Na)-MOFs(Ln=Tb、Dy、Ho)的晶体结构及对乙醛、Fe3+、Cr2O72-的荧光传感和邻苯二酚的电化学传感

在溶剂热条件下合成了3个新型三维微孔同构异核金属有机骨架Ln （Na）-MOFs：{[LnNa （BDT）（H₂O）₃]·2H₂O}_n（Ln=Tb （1）、Dy （2）、Ho （3）,H₄BDT=3,5-二（3'',5''-二羧基苯基）-1H-1,2,4-三唑）,并通过单晶X射线衍射、元素分析、热重分析和粉末X射线衍射技术对其进行表征。结构分析表明,Ln （Na）-MOFs是具有相同的异核双金属单元的三维骨架结构。荧光研究表明,Tb （Na）-MOF （1）可以荧光传感检测水中Fe³⁺、Cr₂O₇^2-以及乙醛分子,具有较高的灵敏度和选择性,也可用于水中邻苯二酚的电化学检测。     

钴铁双金属氧化物多孔纳米棒的制备及其电解水析氧性能

通过简单的钴铁前躯体热分解法制备了系列一维Co_1-xFe_xO_y（0≤x≤1）多孔纳米材料,并在1 mol·L^-1 KOH溶液中研究了其电解水析氧催化性能。研究发现不同Fe掺杂量对材料的结构与电解水析氧催化性能有较大的影响,其中16%（n/n）Fe掺杂量的Co_1-xFe_xO_y具有最优的析氧催化性能。在10 mA·cm^-2电流密度下其析氧过电位为345 mV,塔菲尔斜率为54 mV·dec^-1,并表现出优异的析氧稳定性能。廉价、高效的Co_1-xFe_xO_y多孔纳米棒材料有望成为优良的析氧催化剂用于电解水制氢。     

一种镉基金属有机骨架材料对丙酮和Fe3+的荧光检测

以1,3,5-三（4-羧基苯基）苯（H₃BTB）为配体,通过溶剂热法得到一种三维四重穿插结构的镉基金属有机骨架材料：（Me₂NH₂）[Cd（BTB）（DMF）]·DMF·H₂O（Cd-MOF）。通过单晶X射线衍射、粉末X射线衍射、红外分析、元素分析和热重分析表征了其组成和结构。荧光研究结果表明：Cd-MOF在含有丙酮或Fe³⁺离子的溶液中均表现出荧光猝灭现象,其检测限（体积分数和浓度）分别为0.6%和0.89 μmol·L^-1,线性检测范围分别为2.0%~2.8%和0~0.05 mmol·L^-1。时间响应实验和可循环利用实验显示Cd-MOF可长时间、稳定且高效地检测丙酮和Fe³⁺离子。     

基于2-(4'-羧基苯基)咪唑-4,5-二羧酸构筑的三个镉/锌配位聚合物的合成、拓扑结构、荧光光谱及DNA作用

以2-（4''-羧基苯基）咪唑-4,5-二羧酸（H₄CPhIDC,C₁₂H₈N₂O₆）为配体,用溶剂热合成了3种配位聚合物{[Cd₂（CPhIDC）（bimb）]·H₂O}_n（1）、{[Cd₂（CPhIDC）（phen）₂]·3H₂O}_n（2）、{[Zn₂（CPhIDC）（bpp）]·1.5H₂O}_n（3）（bimp=1,4-双咪唑基-丁烷,phen=1,10-菲咯啉,bpp=1,3-双（4-吡啶基）-丙烷）。用元素分析、红外光谱、粉末X射线衍射和单晶X射线衍射对配合物进行了表征和结构分析。结构分析表明,主配体以完全去质子化CPhIDC^4-的形式与中心金属离子形成以μ₄和μ₅为配位模式的二维及三维聚合物。配合物1和3是三维网络结构,同时呈现（3,4,5）-连接的（5·6·7）（4·5²·6·7²）（4·5²·6·7⁴·8²）拓扑结构,两者的不同之处是中心离子和辅助配体。配合物2是二维波纹状渔网结构,呈现4⁴·6²拓扑结构,在其空间填充上又类似于DNA双螺旋链的单螺旋结构。测定了产物的固体荧光光谱;用EtBr荧光探针法研究了配体及配合物与ct-DNA的相互作用。     

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。     

两个基于Cd(Ⅱ)金属有机骨架化合物在金属离子和有机分子发光传感中的应用

合成了2个镉（Ⅱ）金属有机骨架化合物{[Cd（L）（fma）]·0.5H₂O}_n（1）和{[Cd（L）_0.5（sdb）]·DMF}_n（2）（L=E,E-2,5-二己氧基-1,4-双（2-乙烯-吡啶基）苯,H₂fma=延胡酸,H₂sdb=4,4''-磺酰基二苯甲酸）,研究了它们在金属离子和有机分子的发光传感中的应用。结果表明,Fe³⁺对配位聚合物1和2的发光强度有明显的猝灭作用。此外,聚合物1和2还对水杨醛具有明显的猝灭能力。     

木糖-软模板水热法制备硼掺杂分级多孔炭球及其电化学性能

以D-木糖为炭源,月桂酸钠为模板剂,硼酸为掺杂剂,通过水热炭化方法制得硼掺杂分级多孔炭球（BPC_S）。通过扫描电子显微镜（SEM）、透射电子显微镜（TEM）、N₂吸附-脱附测试、X射线光电子能谱（XPS）、顺磁共振波谱（EPR）、傅里叶红外光谱（FT-IR）、拉曼光谱（Raman）、X射线粉末衍射（XRD）、热重（TG）分析对样品进行表征。结果表明：月桂酸钠作为介孔造孔剂的同时,通过与D-木糖间的氢键作用使有机-有机自组装过程自发进行并形成窄尺寸分布（2~5 μm）规整炭球;硼酸在水热中催化炭源脱水降解,并以BC₃、BCO₂和BC₂O的形式掺杂在炭球上,掺硼后炭球与水表面接触角降低,润湿性提高。经CO₂活化、月桂酸钠高温分解以及胶质炭球的堆积分别产生微孔（0.5~1.2 nm）、介孔（3.14~35.00 nm）和大孔（60~146 nm）并形成分级结构。当硼酸加入量为0.927 5 g时多孔炭球（BPC_S-1）的电化学性能最佳,在6 mol·L^-1 KOH三电极体系中电流密度为0.5 A·g^-1时,比电容达287.12 F·g^-1;两电极体系中电流密度为0.5 A·g^-1时比电容达151.34 F·g^-1,能量密度达5.3 Wh·kg^-1;电流密度为5 A·g^-1时进行1 000次充放电循环,电容保持率仍达96.43%。     

Reduction Dehydration of Iron Oxide Hydroxide by iron metal in aqueous medium

The reductive dehydration of iron hydroxide (FeOOH) by iron metal in aqueous solutions of ferrous sulphate was found to occur. These reactions of α, β, γ FeOOH and Fe(OH)₃ · nH₂O respectively were carried out in 0.01–1 mol iron(II) sulphate solutions and over the temperature range of 80–100°C to produce Fe₃O₄ in all cases. The reaction rate decreases with increasing Fe²⁺ concentration and depends on the total concentration of sulphate anion. The presence of iron(II) chloride has an inhibiting effect.     

The formation of iron carbonyl radical anions in the reactions of iron carbonyls with trimethylamine N-oxide

The interaction of iron carbonyls, Fe(CO)₅, Fe₂(CO)₉ and Fe₃(CO)₁₂ with Me₃NO occurs according to a one-electron redox-disproportionation scheme giving rise to iron carbonyl radical anions: Fe₂(CO)₈^·− (1), Fe₃(CO)₁₂^·− (2), Fe₃(CO)₁₁^·− (3) and Fe₄(CO)₁₃^·− (4). The role of Me₃NO, inducing CO-substitution, consists of the generation of reactive 17-electron species with a labile coordination sphere in which the substitution for other ligands occurs, resulting from fast ligand and electron exchange in the confines of the ETC-reaction.     

Mössbauer Spectroscopic Investigation of FeII and FeIII 3,4,5‐Trihydroxybenzoates (Gallates) – Proposed Model Compounds for Iron‐Gall Inks

Iron gallates with iron in the oxidation states Fe²⁺ and Fe³⁺ were prepared and studied by Mössbauer spectroscopy, X‐ray diffraction, and IR spectroscopy. Fe^III 3,4,5‐trihydroxybenzoate (gallate) Fe(C₇O₅H₄) · 2H₂O, whose structure was first determined by Wunderlich, was obtained by the reaction of gallic acid and metallic iron or by oxidation of the Fe^II gallate, which was obtained by the reaction of ferrous sulfate with 3,4,5‐trihydroxybezoic acid (gallic acid) under anoxic conditions. Trials to reproduce the hydrothermal preparation method of Feller and Cheetham show that the result depends crucially on the free gas volume in the reaction vessel. If there is no free volume one obtains the same Fe^III gallate as in the other preparation methods. With a large free volume another compound was found to form whose composition and structure could not be determined. It could be specified only by Mössbauer spectroscopy. Fe^III gallate, the Fe^II gallate, and the new phase show magnetic ordering at liquid helium temperature.     

Hydrothermal synthesis, crystal structure and magnetic property of oxalate-bridged iron 1D chain coordination polymer

A novel oxalate-bridged iron coordination polymer, Fe₂(phen)₂(C₂O₄)₂ (1) has been hydrothermally synthesized and characterized by elemental analyses, IR spectrum, TGA-DTA analysis, and single-crystal X-ray diffraction. Compound (1) crystallizes in the monoclinic system, space group P2(1), the final R is 0.0486. The tetradentate-chelating coordination mode of oxalate anion creates an infinite 1D iron (II) oxalate chain structure and from which a 2D network is constructed by π–π interactions of phen rings. The temperature-dependent magnetic susceptibility measurement indicates the existence of a weak antiferromagnetic coupling between Fe^II ions.     

Thermal stability of amino acid-(tyrosine and tryptophan) coated magnetites

The thermal stability of two amino acid-(tyrosine and tryptophan) coated magnetite and their corresponding precursors, [Fe₂^IIIFe^II(Tyr)₈]·9H₂O and [Fe₂^IIIFe^II(Trp)₂(OH)₄](NO₃)₂·8H2O (where tyrosine=Tyr and tryptophan=Trp), was analyzed in comparison with free amino acids. The complexes present a lower thermal stability relative to the free ligand, due to the catalytic effect introduced by the iron cation and the presence of NO₃⁻ groups. The presence of NO₃⁻ group determines also a different degradation’s stoichiometry of the amino acid anion comparative with the one expressed by the free ligand molecule. The amino acid bonded to magnetite decomposes in two steps, its presence inducing an increasing of γ-Fe₂O₃→Fe₂O₃ conversion temperature.     

The resonance Raman spectra of intermediate-spin ferrous porphyrin

The resonance Raman and absorption spectra of unligated ferrous octaethylporphyrin [Fe²⁺ (OEP)] and its adduct with 2-MeIm or THF were observed. The resonance Raman spectrum of Fe²⁺ (OEP) in CH₂Cl₂ displayed characteristic features of iron porphyrin with three d_π electrons, suggesting ³E_g as the intermediate-spin (S = 1) ground state. Fe²⁺(OEP) in THF exhibited the ferrous high spin feature like Fe²⁺ (OEP) (2-MeIm) in CH₂Cl₂.     

Synthesis,Crystal Structures,and Magnetic Properties of Three New Iron Complexes Derived from 3,5‐Bis(pyridin‐2‐yl)‐1,2,4‐triazole

Two new iron(III) complexes and one iron(II) complex have been synthesized from the solvothermal reactions of FeCl₃·6H₂O with 3,5‐bis(pyridin‐2‐yl)‐1,2,4‐triazole (Hbpt) in methanol or acetonitrile. KSCN acted as the reducing agent in the synthesis of iron(II) complex of 3 . [FeCl₃(Hbpt)(H₂O)]·H₂O ( 1 ) crystallizes in the triclinic space group with a = 7.475(1), b = 9.468(2), c = 12.309(2) Å, α = 73.880(2), β = 74.746(2), γ = 81.849(2)°, V = 805.2(2) ų, Z = 2. [Fe₂(bpt)₂Cl₄] ( 2 ): orthorhombic space group Pnnm with a = 9.895(2), b = 10.632(2), c = 13.195(2) Å, V = 1388.1(4) ų, Z = 2. [Fe₂(bpt)₂(MeOH)₂Cl₂] ( 3 ): orthorhombic space group Pbca with a = 14.4204(16), b = 9.8737(11), c = 19.792(2) Å, V = 2818.1(5) ų, Z = 4. 1 features the first structurally characterized metal complex of the neutral Hbpt ligand in which the Hbpt ligand adopts an unprecedented zwitterionic form. 2 shows a neutral dinuclear iron(III) complex and the [Fe₂(bpt)₂]⁴⁺ unit is ideally planar. The two iron(III) ions separated by a distance of 4.408(2) Å are doubly triazolate‐bridged. Each dimeric unit is connected with six other dimeric ones via the bifurcated C‐H···Cl hydrogen bonds, these connections extend the dimeric moieties into a three‐dimensional molecular architecture. 3 is a neutral centrosymmetric dinuclear Fe^II complex, in which intermolecular moderate O‐H···N hydrogen bonding interactions between the methanol molecules and 4‐position nitrogen atoms of the triazolato groups extend the dinuclear species into a two‐dimensional supramolecular architecture of (4,4) topology. Magnetic studies indicate there exists an antiferromagnetic spin coupling in Fe^III₂ and Fe^II₂ units via the double triazolate bridges in 2 and 3 .     

A new high-spin iron(III) bis(aqua) complex with the <Emphasis Type="Italic">meso</Emphasis>-tetra(para-chlorophenyl)porphyrin: X-ray crystallography,Hirshfeld surface analysis,magnetic, EPR and electrochemical properties

Chemical preparation of the bis(aqua) iron(III) metalloporphyrin [Fe^III(TClPP)(H₂O)₂](SO₃CF₃)·2(Pnz)·3/4(C₆H₁₂)·2H₂O (TClPP?=?TClPP?=?5,10,15,20-tetra(para-chlorophenyl)porphyrinato and Pnz?=?phenazine) coordination complex (I) was made. The crystal structure of (I) was determined by X-ray single-crystal diffraction and elucidated by Hirshfeld surface approach. Magnetic, spectroscopic and electrochemical properties were also reported and discussed. The mean equatorial distance (Fe–Np) between the iron(III) atom and porphyrin nitrogen atoms is appropriate to a high-spin (S?=?5/2) iron(III) complex. The high-spin state is also confirmed by both magnetic and electron paramagnetic resonance (EPR) spectroscopy data. The repetitive building unit of the crystal structure provides [Fe^III(TClPP)(H₂O)₂]⁺ ion complexes, two non-coordinated Pnz molecules and two water molecules which are interconnected by O–H···O/N/Cl, C–H···O/F/Cl hydrogen bonds, and by C–X···π, C–H···π and π–π stacking intermolecular contacts, forming a 3D supramolecular network. The role and nature of these intermolecular interactions were quantitatively analysed by 3D Hirshfeld surface analysis and associated 2D fingerprint plots. Cyclic voltammetry measurements indicate a one-electron reversible reduction wave with an E_1/2 (Fe(III)/Fe(II) half-potential value of ?0.24 V, which confirms the high-spin S?=?5/2 state of the studied complex.     

多孔朵状Fe_3O_4纳米微球的制备及其性能研究

<正>众所周知,纳米材料的尺寸大小、晶型、形貌构型等结构特征对材料的化学物理性能有重要的影响[1],由于特殊形貌的新材料所具有独特、新颖、高效的化学物理等方面的性质以及在众多领域中的潜在应用[2],特别是3D花状空心纳米结构新物质[3-4],新形貌物质的纳米材料的制备方法和应用特性已经吸引了世界上材料领域的广泛兴趣和关注[5]。目前为止,合成3D纳米结构的方法有自组装法、三维导向连接法以及水热法等,即通过使用有     

中空分级结构Fe3O4@C/rGO复合材料的合成及其储锂性能

以氧化石墨烯(GO)为基底,Fe(NO_3)_3·9H_2O、异丙醇、甘油为原料,通过溶剂热法和后续热处理过程2步合成了Fe_3O_4@C/rGO复合材料,实现了碳包覆的Fe_3O_4纳米粒子自组装形成的分级结构空心球在氧化石墨烯片上的原位生长。采用X射线衍射(XRD)、扫描电镜(SEM)、透射电镜(TEM)和恒流充放电等手段分析了材料的物理化学性能与储锂性能。结果表明,该复合材料在5.0 A·g~(-1)的电流密度下,仍有437.7 mAh·g~(-1)的可逆容量,在1.0 A·g~(-1)下循环200圈后还有587.3 mAh·g~(-1)的放电比容量。这主要归因于还原态氧化石墨烯(rGO)对碳包覆Fe_3O_4分级空心球整体结构稳定性和导电性的提高。