Synthesis and fluorescence properties of Tb(Ⅲ) complexes with pyridine-2,6-dicarboxylic acid derivatives

Two novel ligands named 4-styrylpyridine-2,6-dicarboxylic acid (4-SPDA) and 4-(4-(2-(2, 6-dicarboxypyridin-4-yl)- vinyl)styryl)pyridine-2,6-dicarboxylic acid(DSPDA) and their complexes with Tb(Ⅲ) were synthesized and characterized by infrared spectrometry, 1H nuclear magnetic resonance, elemental analysis and gas chromatograph-mass spectrometry. The ligand synthetic route was optimized. The fluorescence properties of the complex in solid state, in different kind of solvents and in solutions with different pH values were investigated in detail. The results show that the yields of DSPDA and 4-SPDA reach over 78% by Wittig-Horner reaction and other eight pyridine-2, 6-dicarboxylic acid derivatives with different substituents on pyridine ring, and their complexes with Tb(Ⅲ) are also obtained. The fluorescence intensities of the complexes with electron-donating groups are more intense than those of the complexes with electron-withdrawing groups on pyridine ring; fluorescence intensities of the complexes are the strongest in neutral solution (pH=7), and the less the dipole moment of solvent molecule is, the stronger the fluorescence intensity is. It is found that the two ligands (4-APDA and DSPDA) are the good sensitizers for Tb(Ⅲ) ion.

Extraction Equilibria of Trimellitic and [ 1,1′-Biphenyl]-2,2′-dicarboxylic Acid with 1-Octanol, 50%TBP, and 10%TRPO in Kerosene

To explore the feasibility of extracting aromatic acid products from oxidizing coal, two aromatic acids, trimellitic and [1,1′-biphenyl]-2,2′-dicarboxylic acid, were selected as the solutes, and the extraction equilibrium of the acids were studied with 1-octanol, 50% tributyl phosphate （TBP） in kerosene, and 10% trialkylphosphine oxide （TRPO） in kerosene. The results showed that the degree of extraction of [1,1′-biphenyl]-2,2′-dicarboxylic acid was larger than that of trimellitic acid for all of the solvent, and the extraction capacity with TRPO is more effective than the one with TBP. The extraction behavior of aromatic polyacid is different from that of carboxylic acid, and the reactive extraction function of aromatic acids with TBP and TRPO is not as effective as that of carboxylic acid. 1-octanol could be used to remove [1,1′-biphenyl]-2,2′-dicarboxylic acid from the mixture of trimellitic acid and [1,1′-biphenyl]-2,2′-dicarboxylic acid. Because the weak hydrogen bond association exists between -OH in 1-octanol and -COOH in aromatic acid, the extractive selectivity of [ 1, 1′-biphenyl]-2,2′-dicarboxylic to trimellitic acid depends on the stoichiometric ratio.

Synthesis,Crystal Structure and Magnetic Behavior of a New Manganese(Ⅱ) Coordination Polymer [Mn(DPPZ)(PZDC)(H_2O)] (DPPZ=Dipyrido[3,2-a:2',3'-c]-phenazine and H_2PZDC=Pyrazine-2,3-dicarboxylic Acid)

The title complex, [Mn（DPPZ）（PZDC）（H2O）] 1 （DPPZ = dipyrido[3,2 -a：2＇,3＇- c]phenazine and H2PZDC = pyrazine-2,3-dicarboxylic acid）, has been hydrothermally synthesized and structurally characterized by X-ray single-crystal diffraction, elemental analyses, IR, TG- DTA and magnetic susceptibility measurement. It crystallizes in triclinic, space group P1^- with a = 6.6842（5）, b = 7.5741（6）, c = 20.5755（15）A, α = 90.1160（10）, β = 97.0560（10）, γ = 97.3350（10）°, V= 1025.16（13）A^3, Z = 2, MnC24H14N6O5, Mr= 521.35, Dc= 1.689 g/cm^3, F（000） = 530, μ（MoKa） = 0.699 mm^-1, R = 0.0366 and wR = 0.0810. Compound 1 contains one- dimensional chains which are further stacked through π-π interactions to form a 3D supramolecular architecture. The water molecule O（1W） is involved in hydrogen bonding interactions with symmetric carboxylate oxygen atom 0（4） at （x＋ 1, y＋1, z） and symmetric PZDC nitrogen atom N（6） at （1-x, 1-y, 1-z）, which completes the structure of 1. Magnetic susceptibility measurement indicates that the compound behaves a weak antiferromagnetic exchange interaction.

Synthesis,Crystal Structure and Theoretical Calculations of a Zinc(Ⅱ) Coordination Polymer Assembled by Pyrazine-2,3-dicarboxylic Acid and Bis(imidazol) Ligands

A new metal-organic coordination polymer [Zn（pzdc）（mbix）]n·nH2O（H2pzdc = pyrazine-2,3- dicarboxylic acid, mbix = 1,3-bis（imidazol-1-ylmethyl）-benzene） 1 has been hydrothermally synthesized and structurally characterized by elemental analysis, IR, TG, fluorescence spectrum and single-crystal X-ray diffraction. Yellow crystals crystallize in monoclinic system, space group P21/n with a = 8.5519（6）, b = 14.8764（10）, c = 16.4108（11） A, β = 103.4520（10）o, V = 2030.5（2）A^3, C（20）H（18）N6O5Zn, Mr = 487.77, Dc = 1.596 g/cm^3, F（000） = 1000, Z = 4, μ（MoK α） = 1.257 mm^-1, the final R = 0.0260 and w R = 0.0706 for 3445 observed reflections（I 〉 2σ（I））. The structure of 1 exhibits a one-dimensional chain-like structure. In addition, natural bond orbital（NBO） analysis was performed by the PBE0/LANL2DZ method in Gaussian 03 Program. The calculation results show obvious covalent interaction between the coordinated atoms and Zn（Ⅱ） ion.

Crystal Structure and Theoretical Studies of Tetrahytrate(1-H-1,2,4-triazole-3,5-dicarboxylicacid)nickel

A new compound, [Ni（Hdctrz）（H2O）4]（1, H3dctrz = 1-H-1,2,4-triazole-3,5-dicarboxylic acid）, has been successfully synthesized via slow evaporation. The structure of 1 was characterized by FT-IR, elemental analysis and single-crystal X-ray diffraction. Compound 1 crystallizes in monoclinic, space group P21/c with a = 6.871（1）, b = 11.468（1）, c = 12.178（1） A, b = 101.291（1）o, V = 941.01（16） A3, Z = 4, C4H9N3O8Ni, Mr = 285.85, Dc = 2.018 g·cm–3, m = 2.10 mm–1, F（000） = 584, GOOF = 1.025, the final R = 0.0515 and wR = 0.2125 for 1404 observed reflections（I 〉 2s（I））. The crystal structure is assembled by a slightly distorted {NiNO5} octahedral geometry and hydrogen bonds viz. N–H…O, O–H…O, C–O…π and π···π weak interactions. A rare π···π interaction from triazolate and carboxylate is affirmed through the molecular orbitals（MO） of three adjacent Ni CN molecules. The 3D Hirshfeld surface analysis was employed to gain additional insight into the interactions responsible for the packing of compound 1. Quantitative examination of 2D fingerprint plots revealed, amongst others, the dominating participation of O···H, N···H and π···π interactions in the molecular packing.

2D-QSAR Studies on Anthranilic Acid Derivatives: A Novel Class of Allosteric Inhibitors of Hepatitis C NS5B Polymerase

Quantitative structure activity relationship （QSAR） studies were performed on 45 anthranilic acid derivatives for their potent allosteric inhibition activities of HCV NSSB polymerase. Genetic algorithm based genetic function approximation （GFA） method of variable selection was used to generate the model. Highly statistically significant model with r^2 = 0.966 and r^2cv = 0.951 was obtained when the number of descriptors in the equation was set to 5. High r^2pred value of 0.884 indicates the good predictive power of the best model. Spatial descriptors of radius of gyration （RadOfGration）, molecular volume （Vm）, length of molecule in the z dimension （Shadow-Zlength）, thermodynamic descriptors of the octanol/water partition coefficient （LogP） and molecular refractivity index （MR） showed enormous contributions to HCV NS5B polymerase inhibition. The validation of the model was done by leave-one-out （LOO） test, randomization tests and external test set prediction. The model gives insight on indispensable structural requirements for the activity and can be used to design more potent analogs against HCV NSSB polymerase.

Hydrothermal Synthesis, Crystal Structure and Thermal Analyses of Pyrazine-2,3-dicarboxylic Acid Bridged Co(II) Coordination Polymer of _∞~2[Co(phen)(μ-L)_(3/3)]·H_2O (H_2L = Pyrazine-2,3-dicarboxylic Acid)

A novel pyrazine-2,3-dicarboxylic acid bridged Co(II) phen complex 2 ∞ [Co- (phen)(μ-L)3/3]?H2O (H2L = pyrazine-2,3-dicarboxylic acid) has been hydrothermally synthesized, and X-ray single-crystal diffraction analysis shows that it crystallizes in the monoclinic system, space group P21/n with a = 11.480(2), b = 11.885(2), c = 12.939(3) ?, β = 110.55(3)°, V = 1653.1(6) ?3, Mr = 423.25, Dc = 0.425 g/cm3, Z = 4, R = 0.0361 and wR = 0.1011. The title complex consists of 2D 2 ∞ [Co(phen)(μ-L)3/3] layers and crystal water molecules. Each Co atom is octahedrally coordinated by three N atoms and three O atoms to form 2D 2 ∞ [Co(phen)(μ-L)3/3] polymeric layers. Furthermore, such 2D layers are stacked into 3D supramolecular frameworks via Van der Waals’ intermolecular forces, strong and weak hydrogen-bond interactions. The coordination phen and crystal water molecules are resided into cavities of the frameworks.

Structure and Photoluminescence of a 3D Coordination Polymer from Triazole and 2,6-Dimethylpyridine-3,5-dicarboxylic Acid

A new metal-organic coordination polymer [Zn2（trz）2（mpda）（H2O）]n（1, trz = 1,2,4-triazole, H2 mpda = 2,6-dimethylpyridine-3,5-dicarboxylic acid） was synthesized and characterized by single-crystal X-ray analyses. The crystal is of monoclinic system, space group P21/n, a = 9.619（3）, b = 8.920（3）, c = 22.159（6）, β = 96.897（4）°, V = 1887.3（9）3, Z = 4, Mr = 478.04, D3 c = 1.682 Mg/m, F（000） = 960, the final R = 0.0264 and wR = 0.0870（I 2σ（I））. Compound 1 consists of {[Zn4（trz）4]4＋}n layers, which are further connected by mpda2- to complete a three-dimensional structure. The title compound exhibits luminescence at λmax = 415 nm upon excitation at 364 nm.

2D-QSAR Studies on Phenoxybenzoic Acid Derivatives: A Novel Class of 5a-Reductase Inhibitors

The quantitative structure-activity relationship （QSAR） of 14 phenoxybenzoic acid derivatives was studied by ab initio method at the HF/6-31G level using Guassian03 software. The optimized structures together with some characteristic and electric parameters of the title compounds were obtained; some stereo-parameters were calculated by HyperChem software. Stepwise multiple regression and principal component regression methods are adopted to establish multi-parametric models between biological activity and parameters. The results indicated that the lager Ehomo, M, V and LogP, the smaller Etumo and S, and the higher biological activity. A theoretical direction was provided to synthesize some compounds with high activity.

γ-Mo_(2)N/C催化剂的合成及其甲酸脱氢性能研究

甲酸(FA)因其H含量较高(4.4%)、易产H_(2)、可经小平台化合物合成等优势受到广泛关注,而γ-Mo_(2)N/C对FA沿H_(2)和CO_(2)路径分解具有非常高的选择性,产生CO极少,显示出较高的应用价值。基于此,本研究采用对苯二胺和钼酸铵水溶液经前驱体制备γ-Mo_(2)N/C催化剂,并对其FA分解性能进行了原位评价,采用热重分析(TG)、X射线衍射(XRD)、傅里叶变换红外光谱(FT-IR)、扫描电镜(SEM)、透射电镜(TEM)等表征手段对催化剂的结构和表面官能团进行了分析,利用DFT对FA在γ-Mo_(2)N (200)晶面的吸附构型进行了计算,在此基础上,对催化剂性能及FA在其表面的分解机理进行了研究。结果表明,γ-Mo_(2)N/C在较低温度下即可表现出极高的催化活性,提高γ-Mo_(2)N在C载体上的分散性能有效改善FA转化率。对苯二胺与钼酸铵的物质的量比为4∶1时,催化性能最佳,在160℃、100 h的FA分解实验中,催化剂性能稳定、H_(2)选择性高(N_(2)40 mL/min, CO<5.0×10^(-5))。而DFT计算表明,FA中O-H键的H原子与γ-Mo_(2)N/C (200)晶面上N原子结合的可能性更大,而C=O键的O原子更有可能与γ-Mo_(2)N/C (200)晶面上Mo原子结合。上述结果有助于明确FA在γ-Mo_(2)N/C作用下的分解机理,也显示出非贵金属催化剂γ-Mo_(2)N/C在FA分解制H_(2)方面潜在的应用前景。

Binary and Ternary Complexes of Cd（ll） Involving Pyrazine 2,3-Dicarboxylic Acid and Various Biologically Relevant Ligands

Binary and ternary complexes of Cd（II） involving pyrazine 2,3-dicarboxylic acid （pzdca） and various biologically relevant ligands containing different functional groups are investigated at 25 ℃, I = 0.10 M （NaNO3） and in 20% （v/v） ethanol-water media. The ligands （L） used are amino acids, dicarboxylic acids and peptides. The results showed the formation of Cd （pzdca） （L） complexes with amino acids and dicarboxylic acids. Peptides form both Cd （pzdca） （L） complexes and the corresponding deprotonated amide species Cd （pzdca） （LH-1）. The relative stabilities of ternary complexes are compared with those of the corresponding binary complexes in terms of AlogK values. The concentration distribution of the complexes in solution was evaluated.

Two Nickel(Ⅱ) Complexes Constructed by Novel Bis(3-methoxy-2-pyridyl)ether-6,6′-dicarboxylic Acid Ligand:Lattice Water Control of Structure

Under given conditions, two complexes of [Ni（H20）2BEDA]·2H2O 1 and [Ni（Py）2- BEDA]·6H2O 2 （BEDA = bis（3-methoxy-2-pyridyl）ether-6,6′-dicarboxylic acid） have been synthesized and characterized by elemental analysis and X-ray single-crystal diffraction. Crystal data for 1： C14H18NiN2O11, monoelinic C2/c, a = 14.3844（17）, b = 12.9900（15）, c = 9.6309（11） A, β = 104.3350（10）°, V= 1743.5（4） A3, Z = 4, Dc= 1.711 g/cm^3, F（000） = 928, μ = 1.179 mm^-1, Mr= 449.01, the final R = 0.0228 and wR = 0.0625. Crystal data for 2： C24H32NiN4O13, triclinic P1, a = 9.423（2）, b = 11.863（3）, c = 13.089（3） A, α = 91.511（3）, β = 92.465（3）, γ = 100.696（2）°, V = 1435.6（6） A^3, Z = 2, Dc= 1.488 g/cm^3, F（000） = 672, μ = 0.748 mm^-1, Mr= 643.25, the final R = 0.0400 and wR = 0.0975. Interestingly, in the two complexes, lattice water molecules dominate its crystal structures. Therefore, extensive intermolecular hydrogen bonds assemble 1 and 2 into 2D extended sheets and a 3D open framework, respectively. Furthermore, water molecules present in 2 are associated to form water clusters.

STUDIES ON THE SYNTHESIS OF D-GLUCURONIC ACID DERIVATIVES OF 2-BUTOXY-5-FLUORO-3H-4-PYRIMIDONE AND THEIR ANTICANCER ACTIVITIES

2-Butoxy-5-fluoro-3H-4-pyrimidone derivatives of D-glucuronic acid having 0-glycosidic linkage or N-glycosidic linkage were synthesized and their anticancer activity tested.Their structures were confirmed by elementary analysis,IR spectra and ~1HNMR.

马铃薯三糖甘草次酸衍生物通过抑制SARS-CoV-2进入靶细胞作为潜在的小分子新冠病毒融合抑制剂

目的 研究马铃薯三糖甘草次酸衍生物能否通过抑制SARS-CoV-2进入靶细胞,作为潜在的小分子新冠病毒融合抑制剂。方法 以天然SARS-CoV-2进入抑制剂甘草酸为先导化合物,利用活性亚结构的拼合原理等设计并合成了系列马铃薯三糖甘草次酸衍生物。利用SARS-CoV-2假病毒体外细胞感染模型,检测该系列甘草次酸衍生物的体外抗SARS-CoV-2活性;利用表面等离子共振技术及假病毒模型寻找先导化合物1b的抗病毒作用靶点;利用SARS-CoV-2 S蛋白介导的细胞-细胞融合体系,检测先导化合物1b是否作用于SARS-CoV-2病毒入侵宿主的膜融合过程;基于分子对接与定点突变技术,确定先导化合物1b与S蛋白的作用模式等。结果 先导化合物1b对SARS-CoV-2奥密克戎假病毒有显著抑制作用,EC50值为3.28μmol/L(P<0.05),对其它SARS-CoV-2变异株假病毒有广谱抗病毒活性。细胞-细胞膜融合实验显示1b能够抑制合胞体的形成。分子对接预测先导化合物1b可与S1与S2亚基交界处的空腔中的Glu309、Ser305、Arg765、Lys964等多个保守氨基酸残基产生氢键作用,亲和力为-8.6 kcal/mol。化合物1b在10、5、2.5、1.25μmol/L时对Arg765、Lys964、Glu309和Leu303突变后的假病毒的抑制活性显著降低(P<0.01)。结论 马铃薯三糖甘草次酸衍生物能够靶向作用于S蛋白,特异性干扰病毒-细胞膜融合阶段,继而发挥抗SARS-CoV-2感染的作用,是一类结构新颖的小分子SARS-CoV-2融合抑制剂。

The Friedel-Crafts Acylation of Substituted Benzene with 2 - Phenylfuran-3, 4-dicarboxylic Acid Anhydride

2-Phenylfuran-3,4-dicarboxylic acid anhydride reacted with seven aromatic compounds, of which five gave keto acids in yields of 94%-63%. The structure of the keto acid was elucidated by reducing it to hydroxy acid and analyzing with NMR technique.

The First Two-dimensional Supramolecular Network Constructed by Na(Ⅰ) with 2-Methylimidazole-4,5-dicarboxylate Building Blocks

The title complex [Na（H2MIA-）（H2O）]（1,H3MIA = 2-methyl-1H-imidazole-4,5-dicarboxylic acid） has been synthesized by hydrothermal synthesis and structurally characterized by X-ray crystallography.Compound 1 crystallizes in orthorhombic,space group ibam with a = 14.4737（19）,b = 17.553（2）,c = 6.5285（9）,V = 1658.6（4） 3,C6H7N2NaO5,Mr = 210.12,Z = 8,Dc = 1.675 g/cm3,F（000） = 864,μ = 0.188 mm-1,λ（MoKα） = 0.071073 ,R = 0.0383 and wR = 0.0987 for 1046 observed reflections（I 2σ（I））.In the structure of 1,each coordination water coordinates with two Na（I） ions at the same time and links the neighboring Na（I） ions to form a one-dimensional Na（I）-water chain.Each H2MIA-ligand links the neighboring Na（I） of Na（I）-water chain to form a novel two-dimensional supramolecular network.The 2-D network is stabilized by O-H…N hydrogen bonds and π-π interaction.The 2D network is further linked via O-H…O hydrogen bonds to yield a three-dimensional framework.

Synthesis,Crystal Structure and Fluorescence Property of a New Trinuclear Nickel(Ⅱ) Complex Bridged by 2,6-Pyridine Dicarboxylic Acid

A new trinuclear nickel complex,[Ni3（pdc）3（2,2＇-bipy）3（H2O）2]·2H2O（H2pdc = pyridine 2,6-dicarboxylic acid,2,2＇-bipy = 2,2＇-bipyridine） has been hydrothermally synthesized and characterized by IR,elemental analysis and X-ray diffraction methods.Crystal data for this complex：monoclinic,space group P21/n,a = 21.206（4）,b = 10.002（2）,c = 28.066（6）,β = 108.18（3）°,C51H41N9Ni3O16,Mr = 1212.06,V = 5.656（2） nm3,Dc = 1.423 g·cm-3,μ（MoKα） = 1.062 mm-1,Z = 4,F（000） = 2488,GOOF = 1.034,the final R = 0.0543 and wR = 0.1237 for 6149 observed reflections with Ⅰ 〉 2σ（Ⅰ）.In the complex,three nickel（Ⅱ） ions are bridged by the pyridine 2,6-dicarboxylic acid groups,and all nickel（Ⅱ） ions are seven-coordinated by nitrogen atoms of 2,2＇-bipyridine and pyridine 2,6-dicarboxylic acid and oxygen atoms from pyridine 2,6-dicarboxylic and water to adopt a severely distorted pentagonal bipyramidal geometry.The emission and excitation peaks of the complex in ethanol solutions are located at 336 and 316 nm,respectively.

A Two-dimensional Anthracene-9,10-dicarboxylate Zinc(Ⅱ) Coordination Polymer Based on Binuclear [Zn_2Cl_2] Nodes: Synthesis, Characterization and Luminescent Properties

A two-dimensional（2D） 44 topological ZnⅡ coordination polymer {[Zn2Cl2（L）（4bpy）2]}∞（H2L = anthracene-9,10-dicarboxylic acid, 4bpy = 4,4ˊ-bipyridine） based on binuclear [Zn2Cl2] nodes has been synthesized and characterized by IR, elemental analysis, X-ray powder diffraction and single-crystal X-ray diffraction analysis. Moreover, the luminescent properties of the correspon- ding compound have been briefly investigated.