电化学合成2,5-二甲氧基-2,5-二氢呋喃甲醇工艺研究

以糠醇为原料,NaBr为电解质,甲醇为溶剂,利用电化学法合成焦袂康酸中间体2,5-二甲氧基-2,5-二氢呋喃甲醇,考察反应时间、NaBr添加量、反应温度对产率的影响。结果表明,反应时间与反应温度对产率有显著影响,NaBr添加量对产率影响不显著。当加入糠醇3 g(24 mmol),恒压15 V,最优条件为反应时间2.4 h,NaBr添加量为1.76 g,反应温度-10℃时,平均电流0.93 A,2,5-二甲氧基-2,5-二氢呋喃甲醇产率为67.9%。

5-羟甲基糠醛路线合成2,5-呋喃二甲酸的研究进展

2,5-呋喃二甲酸(FDCA)是一种能够合成生物基聚酯的重要单体,目前在新型可降解塑料等领域具有广阔的应用前景,如何高效且低廉地制备FDCA已经逐步成为了热点问题。本文系统地综述了近年来通过5-羟甲基糠醛(HMF)路线合成FDCA的主要研究进展,首先介绍了HMF路线和其他路线的联系和区别,解释了HMF路线的优点。其次,详细介绍和分析了由HMF合成FDCA的方法,包括直接氧化法、贵金属催化法、过渡金属催化法、光电催化氧化法、酶催化法和全细胞生物催化法。此外,在介绍上述方法的基础上,说明了这些方法的优缺点,总结了HMF路线制备FDCA目前仍面临的挑战,包括催化剂的选择、改善与开发,反应条件优化和对中间产物的处理,还对未来由HMF路线来制备FDCA的前景进行展望。

电催化5-羟甲基糠醛氧化为2,5-呋喃二甲酸的研究进展

在可持续发展导向下,替代能源需求不断增加,生物质资源的有效利用成为研究焦点。5-羟甲基糠醛(HMF)作为一种生物质基平台化合物,具有广阔的应用前景。通过选择性氧化反应,HMF可以转化为高附加值化合物,如2,5-呋喃二甲酸(FDCA)。近年来,电催化氧化作为一种绿色环保的新型手段,在HMF转化为FDCA的研究中取得了显著进展。然而,这一过程涉及竞争反应,如水氧化,对FDCA的产率和法拉第效率产生影响。催化剂对降低反应能垒、提高产物选择性至关重要,但面临稳定性不足、过电位偏高和酸性环境下活性不足等挑战。聚焦于高效催化剂的研究进展,从贵金属催化剂到非贵金属催化剂和非金属催化剂进行深入探讨,旨在为生物质的高效转化提供有益参考。

Two New Cu(Ⅱ) Coordination Polymers Based on 2,5-Furandicarboxylic Acid and 2,2'-bipyridine:Synthesis and Crystal Structure

Two new Cu（II） coordination polymers, [Cu（FDA）（BPY）（H20）]n （1） and {[Cu（FDA）（BPY）（H2O）].2H2O}n （2） （H2FDA = 2,5-furandicarboxylic acid, BPY = 2,2＇-bipyridine）, have been synthesized and structurally characterized by single-crystal X-ray diffraction as well as elemental analysis and IR. Compound 1 crystallizes in monoclinic, space group P21/c, with a = 7.5915（15）, b = 8.4050（17）, c = 24.204（6） A, β = 99.05（3）°, V= 1525.1（6） A3, Dc = 1.706 g/crn3, C16HI2CuN206, Mr = 391.82, F（000） = 796, μ（MoKa） = 1.470 mm-l, Z = 4, R = 0.0633 and wR = 0.1059 for 2389 observed reflections （1 〉 2a（I））, R = 0.0738, and wR = 0.1098 for all data. Complex 2 belongs to triclinic space group PI with a = 8.8660（18）, b = 8.9112（18）, c = 12.525（3） A, a = 88.41（3）, β = 69.38（3）, γ = 66.95（3）°, V = 845.2（3） A3, Dc = 1.681 g/cm3, CI6HI6CuN2Os, Mr. = 427.85, F（000） = 438, μ（MoKα） = 1.342 mm-1, Z = 2, R = 0.0290 and wR = 0.0690 for 2767 observed reflections （I 〉 2σ（I））, R = 0.0329 and wR = 0.0706 for all data. Complexes 1 and 2 are both coordination polymers with one-dimensional chain structures bridged by the protonated FDA ligands, which are assembled into three-dimensional supramolecular structures through hydrogen bonding interactions and π-π packing interactions between the chains.

糠酸制备生物质基2,5-呋喃二甲酸的研究进展

2,5-呋喃二甲酸(FDCA)作为一种绿色的生物基平台化合物,可广泛应用于聚酯、塑化剂、消防及医药等领域。目前,根据合成FDCA的原料区分,FDCA合成路线分为5-羟甲基糠醛(HMF)路线、糠酸路线和其他原料路线。其中糠酸可由大宗生物质基化学品糠醛氧化制备,糠醛工业化生产使得糠酸制备FDCA路线具有绿色、经济性高的优势。据此,综述了糠酸制备FDCA的4种方法:歧化法、羰基化法、C—H羧基化法以及生物催化法的研究现状,对比分析了各方法的优劣及研究进展。通过对比分析表明:C—H羧基化法是一种反应条件温和、绿色环保的工艺,具有实现规模化生产的潜力。

磁性NiFe_(2)O_(4)负载Ru催化5-羟甲基糠醛选择性氧化合成2,5-呋喃二甲酸

采用水热-煅烧法制备了磁性镍铁尖晶石载体NiFe_(2)O_(4),再采用浸渍-还原法在载体上负载Ru纳米粒子制备Ru/NiFe_(2)O_(4)催化剂。采用X射线衍射(XRD)、N2吸附-脱附(BET)、NH3程序升温脱附(NH3-TPD)、H_(2)程序升温还原(H_(2)-TPR)、X射线光电子能谱(XPS)和电感耦合等离子体发射光谱(ICP-OES)测试对催化剂进行表征分析。结果表明,Ru/NiFe_(2)O_(4)催化剂表面氧物种丰富,相较于载体,负载Ru后催化剂比表面积和表面酸量增加,Ru与载体存在相互作用,这可能是催化剂高活性和高稳定性的关键。将催化剂用于5-羟甲基糠醛(HMF)的选择性氧化,负载Ru后,催化剂催化活性显著提升。对反应条件进行优化,在添加0.08 g KHCO3,氧化剂O2压力为1 MPa,反应温度为80℃,使用0.1 g Ru/NiFe_(2)O_(4)催化剂,在水溶液中反应12 h HMF能完全转化,2,5-呋喃二甲酸(FDCA)产率为98.1%。Ru/NiFe_(2)O_(4)循环使用5次后仍能保持较高的活性,催化剂上活性组分Ru不易浸出,并且催化剂具有磁性能便于与反应溶液分离。为今后工业化催化HMF高效选择性氧化合成FDCA提供参考。

Ru基催化剂选择性催化氧化5-羟甲基糠醛制备2,5-呋喃二甲酸研究进展

2,5-呋喃二甲酸(FDCA)是一种重要的生物质基单体,有望替代对苯二甲酸(PTA)生产可降解的生物质聚酯材料,缓解对化石资源的依赖以及环境的污染。如何经济、高效、绿色地合成FDCA是目前迫切需要解决的难题。5-羟甲基糠醛(HMF)作为典型的生物质平台化合物,来源广泛且绿色可持续,以其为原料催化氧化制备FDCA近年来备受关注。负载型Ru基催化剂由于其催化活性高、选择性好、成本相对合理,被认为是HMF催化氧化制备FDCA良好的催化材料。本文基于HMF不同氧化路线及反应机制,首先概述了不同活性组分Ru基催化剂的发展历程及其在HMF氧化反应中的应用,接着详细分析了碱添加剂、溶剂及载体对反应的影响,并阐释了相应的催化机制,最后对Ru基催化剂在HMF催化氧化制备FDCA中的工业化应用进行了总结和展望。

2,5-Furandicarboxylic acid production via catalytic oxidation of 5-hydroxymethylfurfural:Catalysts,processes and reaction mechanism

Biomass conversion to value-added chemicals has received tremendous attention for solving global warming issues and fossil fuel depletion.5-Hydroxymethylfurfural(HMF)is a key bio-based platform molecule to produce many useful organic chemicals by oxidation,hydrogenation,polymerization,and ring-opening reactions.Among all derivatives,the oxidation product 2,5-furandicarboxylic acid(FDCA)is a promising alternative to petroleum-based terephthalic acid for the synthesis of biodegradable plastics.This review analytically discusses the recent progress in the thermocatalytic,electrocatalytic,and photocatalytic oxidation of HMF into FDCA,including catalyst screening,synthesis processes,and reaction mechanism.Rapid fundamental advances may be possible in non-precious metal and metal-free catalysts that are highly efficient under the base-free conditions,and external field-assisted processes like electrochemical or photoelectrochemical cells.

A Novel Calcium(Ⅱ) Coordination Polymer Based on 2,5-Furandicarboxylic Acid:Synthesis and Crystal Structure

Solvothermal reaction of 2,5-furandicarboxylic acid （H2FDA） ligand and Ca（NO3）24H2O affords a new coordination polymer, [Ca2（FDA）2（DMAC）（H2O）]n （1）. The structure has been determined by single-crystal X-ray diffraction analyses and further characterized by elemental analyses, IR, powder X-ray diffraction and TGA. Compound I crystallizes in triclinic, space group Pi with a = 9.5387（19）, b = 10.425（2）, c = 11.590（2）A, a = 75.02（3）, fl = 84.80（3）, y = 80.99（3）~, V = 1098.1（4） A3, Dc = 1.492 g/cm^3, C16H15Ca2NO12, Mr = 493.45, F（O00） = 508, p（MoKa）= 0.580 mm-1, Z= 2, R = 0.0436 and wR = 0.0944 for 3865 observed reflections （I〉 2σ（/））, and R --- 0.0595 and wR = 0.1015 for all data. The structure of 1 exhibits a three-dimensional network with layer-pillar structure.

Two New Main Group Metal Coordination Polymers Based on 2,5-Furandicarboxylic Acid: Syntheses and Crystal Structures

By using solvothermal method, two new main group metal coordination polymers based on 2,5-furandicarboxylic acid （H2FDA） ligand, [Sr2（FDA）E（H2O）5]n （1） and [Ba4（FDA）4（H2O）10]n （2）, were produced and characterized by single-crystal X-ray diffraction analyses, elemental analyses, IR, and powder X-ray diffraction. Compound 1 crystallizes in monoclinic, space group C2/c with a = 13.454（3）, b = 13.426（3）, c = 20.166（4） A, β = 107.06（3）°, V = 3482.4（13）A^3, Dc = 2.188 g/cm^3, CIEH14Sr2O15, Mr = 573.47, F（000） = 2256,μ（MoKα）= 6.21 mm^-1, Z = 8, R = 0.0522 and wR = 0.1229 for 2493 observed reflections （I〉 2σ（I））, and R = 0.0689 and wR = 0.1324 for all data. Compound 2 crystallizes in triclinic, space group el with α = 6.8382（14）, b = 10.932（2）, c = 25.571（5） A,α = 94.64（3）, β= 95.41（3）, γ = 107.83（3）°, V= 1799.4（6） A3, Dc = 2.484 g/cm^3, C24H28Ba4O30, Mr = 1345.82, F（000） = 1272,μ（MoKa） = 4.43 mm^-1, Z = 2, R = 0.0485 and wR = 0.0906 for 5020 observed reflections （I〉 2σ（I））, and R = 0.0706 and wR = 0.0991 for all data. In 1, the trinuclear clusters Sr3 are connected with adjacent four clusters by a carboxylate group to produce a two-dimensional （2D） sheet, which is extended by a FDA-based pillar into a 3D framework. In 2, neighbouring trinuclear clusters Ba3 are linked through two -O-C-O- of FDA^2- ligands to form one-dimensional （1D） chains, which are connected by a FDA-based pillar to construct a 2D framework. The thermal stabilities of 1 and 2 are also investigated.

Two New Mn(Ⅱ)/Co(Ⅱ) Complexes Assembled by 2,5-Dihydroxy-1,4-benzenedicarboxylic Acid and Phenanthroline or Derivative

Two new complexes [Mn(DHTA)(PLQ)]n(1) and{[Co2(DHTA)(phen)2(H2 O)6]· DHTA}n(2)(H2 DHTA = 2,5-dihydroxy-1,4-benzenedicarboxylic acid, PLQ = 1,10-phenanthroline-5,6-quinone, phen = 1,10-phenanthroline) have been hydrothermally synthesized and structurally characterized by elemental analysis, IR spectrum, fluorescence spectrum, single-crystal and power X-ray diffraction. Complex 1 exhibits a two-dimensional(2 D) network, which was stabilized through O–H···O hydrogen bonding interactions. Complex 2 shows a zero-dimensional structure, which was further extended into a three-dimensional supramolecular structure through O–H···O hydrogen bonds and π-π interactions.

High efficient catalytic oxidation of 5-hydroxymethylfurfural into 2,5-furandicarboxylic acid under benign conditions with nitrogen-doped graphene encapsulated Cu nanoparticles

Selective oxidation of 5-hydroxymethylfurfual(HMF) to 2,5-furandicarboxylic acid(FDCA) as a bioplastics monomer is efficiently promoted by a simple system without noble-metal and base additives. In this work, graphene oxide(GO) was first synthesised by an electrochemical method with flexible graphite paper(FGP) as start carbon material, then, nitrogen-doped graphene(NG) layers encapsulated Cu nanoparticles(NPs) was prepared by one-step thermal treatment of GO supported Cu2+ in flowing NH3 atmosphere. Compared with NG supported Cu NPs prepared by the traditional impregnation method, enhanced catalytic activity was achieved over Cu/NG and an FDCA yield of 95.2% was achieved under mild reaction conditions with tert-butylhydroperoxide(t-BuOOH) as the oxidant. Control experiments with different catalysts and different addition procedure of t-BuOOH showed the yield of HMF and various intermediates during reaction. From the changing of intermediates concentrations and reaction rates, a reaction pathway through HMF-DFF-FFCA-FDCA was proposed. This work gives a more convenient, more green,more economical and effective method in encapsulated metal NPs preparation and high selectivity in HMF oxidation to FDCA under mild conditions.

Crystal Structures and Luminescent Properties of Three Coordination Polymers Based on 2,5-Furandicarboxylic Acid Ligand and 1,10-Phenanthroline

Three new coordination polymers,namely [Zn（FDA）（phen）（H2O）·H2O]n（1）,[Cd（HFDA）（phen）2（NO3）]（2） and [Cd（FDA）（phen）]n（3）（H2FDA = 2,5-furandicarboxylic acid,phen = 1,10-phenanthroline） have been synthesized by the solvothermal method and characterized by elemental analysis,IR,powder X-ray diffraction,thermogravimetric analysis and X-ray single-crystal diffraction analysis.For 1,the neighboring Zn^2＋ ions are bridged by FDA2-as linkers to form one-dimensional（1D） chains,and phen ligands are as the terminal ligands.Furthermore,the 1D chains are packed into a three-dimensional（3D） supramolecular structure through hydrogen bonds and π-π interactions.For 2,the H2FDA ligand is partial deprotonation,which is a rare phenomenon among other coordination polymers based on H2FDA.Under the synergetic effect of phen ligands and the partial deprotonation of H2FDA,the structure of 2 is discrete.For 3,the Cd^2＋ ions are linked by two carboxylates of FDA^2-ligand to give rise to 1 D zig-zag chains,and phen ligands chelate the Cd^2＋ ions like 1.In addition,solid-state luminescent spectra of three coordination polymers were also studied at room temperature.

Construction of a New Two-fold Interpenetrated Three-dimensional Cobalt(Ⅱ)Coordination Polymer Based on 2,5-Thiophenedicarboxylic Acid and Bis(imidazol-1-yl)methane

A cobalt coordination polymer, {[Co2（tdc）2（bimm）2]·（3 DMF）}n, was synthesized based on 2,5-thiophenedicarboxylic acid（H2 tdc） and bis（imidazol-1-yl）methane（bimm） mixed ligands. The asymmetric unit of the complex contains two Co2＋） cations, two tdc2-dianions, two neutral bimm ligands, and three free DMF molecules. In the complex, deprotonated tdc2-dianions alternately bridge the adjacent Co2＋ cations to generate chains, which are further connected by the flexible bimm ligands to form a 3 D structure containing adamantanoid-like subunits. In topology, the structure of 1 represents a 4-connected uninodal two-fold interpenetrated dia（66） topology. Moreover, the solid UV-Vis absorption spectra of the complex have also been investigated.

Synthesis and Characterization of Poly(terephthalic acid-2,5-furandicarboxylic acid-1,8-octanediol) Copolyester

Terephthalic acid,2,5-furandicarboxylic acid and 1,8-octanediol were adopted as monomers and antimony trioxide as catalyst,and poly(terephthalic acid-2,5-furandicarboxylic acid-1,8-octanediol) copolyesters identified as PEOT-x,where x is the mole fraction of furandicarboxylic acid in the samples,were synthesized by direct esterification.The molecular structure of the copolyesters was characterized by FTIR and 1H NMR spectroscopy.Gel permeation chromatography (GPC),differential scanning calorimetry (DSC),and thermogravimetric analysis (TGA) were used to characterize the molecular weight,molar mass dispersity,glass transition temperature,and thermal stability of the copolyesters,respectively.The mechanical properties of the samples were also investigated.The number-average molecular weight (M_(n)) of the samples varies from 9 700-18 800 g/mol,and molar mass dispersity (■=M_(w)/M_(n)) from 2.15-3.34.The initial decomposition temperature of the copolyesters is in the 332-356 ℃ range,with maximum decomposition rates at 390-410 ℃,while the glass transition temperature (Tg) varies from 0-33 ℃.Mechanical test shows that PEOT-10 has the highest tensile strength,while PEOT-90 has the largest tensile modulus and elongation at break.The experimental results show that these copolyesters can be synthesized with relatively high molecular weights,good thermal stability,and fair mechanical properties,which makes them excellent replacements for commercial polyesters,such as PET,and these properties can be tuned through the relative amounts of biomass monomer 2,5-furandicarboxylic acid used in the reactions.

A new approach for the aerobic oxidation of 5-hydroxymethylfurfural to 2,5-furandicarboxylic acid without using transition metal catalysts

The organic compound 2,5-furandicarboxylic acid（FDCA） has been identified by the US Department of Energy（DOE） as a valuable platform chemical for a wide range of industrial applications. Currently, the most popular route for FDCA synthesis is reported to be the oxidation of 5-hydroxymethylfurfural（HMF）by O_2 over the catalysis of noble metals（e.g., Au, Pt, Ru, and Pd）. However, the high costs of noble metal catalysts remain a major barrier for producing FDCA at an industrial scale. Herein, we report a transition metal-free synthesis strategy for the oxidation of HMF to FDCA under O_2 or ambient air. A simple but unprecedented process for the aerobic oxidation of HMF was carried out in organic solvents using only bases as the promoters. According to the high performance liquid chromatography（HPLC） analysis, excellent product yield（91%） was obtained in the presence of NaOH in dimethylformamide（DMF） at room temperature（25 ℃）. A plausible mechanism for the NaOH-promoted aerobic oxidation of HMF in DMF is also outlined in this paper. After the reaction, the sodium salt of FDCA particles were dispersed in the reaction mixture, making it possible for product separation and solvent reuse. The new HMF oxidation approach is expected to be a practical alternative to current ones, which depend on the use of noble metal catalysts.

Syntheses, Structures and Magnetic Properties of Two Co(II) Coordination Polymers with 2,5-Pyridine Dicarboxylic Acid

The hydro(solvo)thermal reactions of cobalt powder or its chloride with 2,5- pyridine dicarboxylic acid (H2PYDC) yielded two new complexes: [Co(II)2(PYDC)2(H2O)2- (H2O)4]n 1 and {Co(II)[NH2(CH3)2]2(PYDC)2}n 2. It is observed that the reactive solvents result in different connectivity modes of ligand and diverse dimensional extension of crystal structures. The correlation between structure and magnetic property will be discussed in this paper. Crystal data for 1: space group P1, a = 7.0419(17), b = 8.937(2), c = 9.6182(19) ?, α = 91.532(4), β = 99.869(10), γ = 107.889(11)o, V = 565.5(2) ?3, Z = 1, Dc = 1.845 g/cm3, μ = 1.56 mm-1, F(000) = 322 , R = 0.0505 and wR = 0.1580; and those for 2: space group C2/c, a = 14.9075(6), b = 8.2523(3), c = 16.9643(2) ?, β = 100.982(2)o, V = 2048.75(11) ?3, Z = 4, Dc = 1.560 g/cm3, μ = 0.892 mm-1, F(000) = 996, R = 0.0443 and wR = 0.1134.

2,5-呋喃二甲酸工业废水处理方法研究

为探讨发酵法合成2,5-呋喃二甲酸工业废水的处理方法,经“萃取+共沸-水蒸气精馏+改性活性污泥处理+芬顿氧化”系统处理,达到去除有害部分(菌类、溶剂和其他有机物)和留存有用部分(生产培养基的组成成分)的目的,采用COD值由数万单位降低为2000以内,AN3-N值由数百单位,降低至20以内,将2,5-呋喃二甲酸发酵工业废水处理为可以重复利用的生产培养基配制水。结果表明:该废水处理方法具有科学、易操作和经济实用性,是解决发酵工业废水处理难题的高效新方法。

Eu-2,5-二溴对苯二甲酸金属有机框架的合成及其对铀酰离子的荧光识别

在溶剂热条件下,利用2,5-二溴对苯二甲酸与六水合硝酸铕合成得到一例新型稀土金属有机框架材料Eu(DBTA)_(1.5)(DEA)(H_(2)O)(H_(2)DBTA=2,5-二溴对苯二甲酸;DEA=N,N-二乙基乙酰胺),对其进行红外、热重、粉末衍射和光致发光等手段表征。晶体结构分析表明,Eu^(3+)处于八配位的四方反棱柱中心,通过不同2,5-二溴对苯二甲酸根的桥联作用,形成二维层状结构。该MOF作为荧光探针对UO_(2)^(2+)离子具有高选择性和灵敏性的检测能力,其检出限为6.2×10^(-5)mol/L。此外,通过PXRD、紫外光谱等手段系统地研究了响应过程中的荧光猝灭机制。

2,5-二苄氧基苯甲酸的制备

以乙醇为溶剂 ,KI为催化剂 ,用苄基氯对活泼试剂 2 ,5 -二羟基苯甲酸进行羟基保护得到 2 ,5 -二苄氧基苯甲酸 ,收率 6 4 %。