The title compound glycin.3,5-dihydroxybenzoic acid (GDB) has been synthesized and characterized by single-crystal X-ray analysis. It crystallizes in orthorhombic, space group Pca21 with a = 25.513(10), b = 4.668...The title compound glycin.3,5-dihydroxybenzoic acid (GDB) has been synthesized and characterized by single-crystal X-ray analysis. It crystallizes in orthorhombic, space group Pca21 with a = 25.513(10), b = 4.668(2), c = 9.150(4) A°, Z= 4, V= 1089.8(8) A°^3, C9H13NO7, Mr= 247.20, Dc = 1.507 g/m^3,/z(MoKa) = 0.132 mm^-1, F(000) = 520, R1 = 0.0322 and wR2 = 0.0611 for 885 observed reflections (I 〉 2σ(I)). The title compound is a 1:1 molecular complex of glycin and 3,5-dihydroxybenzoic acid, which is linked by O-H…O and N-H…O hydrogen bonds to form a three-dimensional framework. Test of SHG (second harmonic generation) indicates that NLO generation of the crystal is higher than that of KDP.展开更多
The electrochemical oxidation of 2,5-dihydroxybenzoic acid (1) has been studied in the presence of 1,3- cyclopentadiene (2) as a diene in water/ethanol (40/60, v/v) mixture using cyclic voltammetry and controlle...The electrochemical oxidation of 2,5-dihydroxybenzoic acid (1) has been studied in the presence of 1,3- cyclopentadiene (2) as a diene in water/ethanol (40/60, v/v) mixture using cyclic voltammetry and controlled-potential coulometry. A plausible mechanism for the oxidation of 1 in the presence of 2 is presented. Compound 1 was converted into bis-adduct 5 via electrooxidation, Diels-Alder reaction of 2 to anodically generated 3,6-dioxocyclohexa-l,4-dienecarboxylic acid (lox), decarboxylation reaction, electrooxidation and Diels-Alder reaction. The electrochemical synthesis of 5 was performed in a one- pot reaction, without toxic reagents, at a carbon electrode in a simple cell using an environmentally friendlv method.展开更多
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 structural...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.展开更多
The selective oxidation of 2,5‐bis(hydroxymethyl)furan(BHMF)in this work was proven as a promising route to produce 2,5‐furandicarboxylic acid(FDCA),an emerging bio‐based building‐block with wide application.Under...The selective oxidation of 2,5‐bis(hydroxymethyl)furan(BHMF)in this work was proven as a promising route to produce 2,5‐furandicarboxylic acid(FDCA),an emerging bio‐based building‐block with wide application.Under ambient pressure,the modified carbon nanotube‐supported Pd‐based catalysts demonstrate the maximum FDCA yield of 93.0%with a full conversion of BHMF after 60 min at 60°C,much superior to that of the traditional route using 5‐hydroxymethylfurfural(HMF)as substrates(only a yield of 35.7%).The participation of PdH_(x) active species with metallic Pd can be responsible for the encouraging performance.Meanwhile,a possible reaction pathway proceeding through 2,5‐diformylfuran(DFF)and 5‐formyl‐2‐furancarboxylic acid(FFCA)as process intermediates is suggested for BHMF route.The present work may provide new opportunities to synthesize other high value‐added oxygenates by using BHMF as an alternative feedstock.展开更多
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...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。展开更多
文摘The title compound glycin.3,5-dihydroxybenzoic acid (GDB) has been synthesized and characterized by single-crystal X-ray analysis. It crystallizes in orthorhombic, space group Pca21 with a = 25.513(10), b = 4.668(2), c = 9.150(4) A°, Z= 4, V= 1089.8(8) A°^3, C9H13NO7, Mr= 247.20, Dc = 1.507 g/m^3,/z(MoKa) = 0.132 mm^-1, F(000) = 520, R1 = 0.0322 and wR2 = 0.0611 for 885 observed reflections (I 〉 2σ(I)). The title compound is a 1:1 molecular complex of glycin and 3,5-dihydroxybenzoic acid, which is linked by O-H…O and N-H…O hydrogen bonds to form a three-dimensional framework. Test of SHG (second harmonic generation) indicates that NLO generation of the crystal is higher than that of KDP.
基金the Bu-Ali Sina University Research Council and Center of Excellence in Development of Environmentally Friendly Methods for Chemical Synthesis(CEDEFMCS) for their support of this work
文摘The electrochemical oxidation of 2,5-dihydroxybenzoic acid (1) has been studied in the presence of 1,3- cyclopentadiene (2) as a diene in water/ethanol (40/60, v/v) mixture using cyclic voltammetry and controlled-potential coulometry. A plausible mechanism for the oxidation of 1 in the presence of 2 is presented. Compound 1 was converted into bis-adduct 5 via electrooxidation, Diels-Alder reaction of 2 to anodically generated 3,6-dioxocyclohexa-l,4-dienecarboxylic acid (lox), decarboxylation reaction, electrooxidation and Diels-Alder reaction. The electrochemical synthesis of 5 was performed in a one- pot reaction, without toxic reagents, at a carbon electrode in a simple cell using an environmentally friendlv method.
基金Supported by the National Natural Science Foundation of China(21031002 and 51073079)the Fundamental Research Funds for the Central Universitiesthe Application and Research in Cutting-edge Technologies in Tianjin Technology Projects in General(K11JCYBJC11100)
文摘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.
文摘The selective oxidation of 2,5‐bis(hydroxymethyl)furan(BHMF)in this work was proven as a promising route to produce 2,5‐furandicarboxylic acid(FDCA),an emerging bio‐based building‐block with wide application.Under ambient pressure,the modified carbon nanotube‐supported Pd‐based catalysts demonstrate the maximum FDCA yield of 93.0%with a full conversion of BHMF after 60 min at 60°C,much superior to that of the traditional route using 5‐hydroxymethylfurfural(HMF)as substrates(only a yield of 35.7%).The participation of PdH_(x) active species with metallic Pd can be responsible for the encouraging performance.Meanwhile,a possible reaction pathway proceeding through 2,5‐diformylfuran(DFF)and 5‐formyl‐2‐furancarboxylic acid(FFCA)as process intermediates is suggested for BHMF route.The present work may provide new opportunities to synthesize other high value‐added oxygenates by using BHMF as an alternative feedstock.
文摘采用水热-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。