查找使用阿拉丁产品的科研文献

Synthesis, characterization, and properties of four lanthanide-based coordination polymers with mixed ligands of 4-((4′-carboxybenzyl)oxy)benzoic acid and oxalic acid

Wen-Xian Chen,Xiang Zhou,Yi-Fen Gao,Qiu-Ping Liu,Gui-Lin Zhuang

A series of lanthanide-based coordination polymers (Ln2(CBOB)2(OX)·H2O, where Ln = Gd (1), Eu (2), Pr (3), and Tb (4); CBOB = 4-[(4′-carboxybenzyl)oxy]benzoate; OX = oxalate), were obtained from the reaction of H2OX, H2CBOB, and Ln(NO3)3 with the metal salts. Single-crystal measurements show that both 1 and 2 feature unique 3-D structures with the [Ln(COO)n(C2O4)m] layers connected by CBOB ligands. Moreover, 1, 3, and 4 are antiferromagnetic and 2 and 4 display obvious luminescence emission peaks. Furthermore, quantum Monte Carlo (QMC) simulations and the experimental results reveal that the magnetic coupling parameters of adjacent Gd(III) ions in 1 are −0.026(2) and −0.0069(3) cm─1.

A new coordination compound based on 3, 3′-bis(1H-tetrazol-5-yl)-4, 4′-azofurazan (H2BTZAF): Preparation, crystal structure, and thermal properties

Chenli Wei,Zeyu Guo,Yongjie Li,Jie Huang

A new nitrogen-rich energetic complex Cd(DMF) 2 BTZAF (1) (DMF= N,N-Dimethylformamide, H 2 BTZAF= 3, 3′-bis(1H-tetrazol-5-yl)-4, 4′-azofurazan) was first synthesized by the reaction of Cd(NO 3 ) 2 ·4H 2 O with 4-amino-3-(5-tetrazolate)-furazan. The compound 1 was characterized by elemental analysis and FT-IR spectrum analysis, respectively. The crystal structure of complex 1 was determined by single-crystal X-ray diffraction. It revealed that 1 crystallizes in the monoclinic space group P2 1 /c. A Cd 2+ ion is coordinated by four N atoms and two O atoms to form a distorted octahedral structure. Among them, four nitrogen atoms are from the four BTZAF 2− ions and the other two oxygen atoms are from two DMF molecules. Moreover, the thermal decomposition behavior of compound 1 was studied with DSC and TG-DTG methods. The non-isothermal kinetic parameters of compound 1 was calculated by Kissinger's method and Ozawa-Doyle's method. In addition, the thermal safety performance and the impact sensitivity of complex 1 were measured and calculated, and the results showed that the synthetic compound has good insensitivity and stability.

Solubility and liquid crystal vertical alignment of polyimides derived from a new diamine: 4-((4-dodecyloxy)phenyl)-2,6-di((4-amino)phenyl)pyridine

Lu-Lu Liu,Xin-Guo Zheng,Zhen Sun,Ying-Han Wang

Photophysical Properties of Ternary RE3+ (RE = Eu, Tb, Sm) Hybrids with β-Diketone Functionalized Linkages and 4-(4-nitrostyryl)pyridine Though Coordination Bonding

Li Yan-Yan,Yan Bing,Guo Lei

In this paper, the organic ligands TTA and TAA are grafted onto the coupling agent to achieve the organic precursors (TTA-Si, TAA-Si) as first ligand and the organic 4-(4-nitrostyryl)pyridine (Nspy) is synthesized as the second ligand. Both of them are coordinated to the rare ions with the carbonyl group and nitrogen atom respectively. After the hydrolysis and copolycondensation between the teraethoxysilane (TEOS) and the ternary rare earth organic complex via the sol–gel process, the chemical bonded hybrid materials are constructed and characterized in detail. The obtained hybrid materials present superior thermal stabilities and regular and homogenous square blocks microstructure. Among the hybrids Eu(TTA-Si) 3 Nspy shows a more strong characteristic emission and longer lifetime than the hybrids Eu(TAA-Si) 3 Nspy, while hybrids Tb(TAA-Si) 3 Nspy exhibits the stronger characteristic emission and longer lifetime than the hybrids Tb(TTA-Si) 3 Nspy. For Sm 3+ hybrid materials, the photoluminescence of Sm(TAA-Si) 3 Nspy is too weak to find in the characteristic emission spectra, meanwhile, Sm(TTA-Si) 3 Nspy has the excellent luminescent intensity.

Solid-liquid equilibrium of 1-[4-(4-hydroxyphenyl)piperazin-1-yl]ethenone in twelve mono-solvents: Solubility determination, Hansen solubility parameter and thermodynamic analysis

Pengshuai Zhang,Ruping Ge,Chunxia Jin,Jixiu Deng,Feiyang Dai,Yameng Wan,Beibei Zhang,Shuwei Yu,Xing Li,En Zhang,Lan Zhang,Lu Zhang

The mole fraction solubility of 1-[4-(4-hydroxyphenyl)piperazin-1-yl]ethenone (1-HPE) in twelve mono-solvent systems namely “2-methoxyethanol (2-ME), methanol (MeOH), ethanol (EtOH), butan-1-ol ( n -BuOH), 2-propoxyethanol (2-PE), propan-2-ol ( i -PrOH), 2-methylpropan-1-ol ( i -BuOH), Acetonitrile (MeCN), ethane-1,2-diol (EG), 2-ethoxyethanol (2-EE), propan-1-ol ( n -PrOH), 2-butoxyethanol (2-BE)” were determined from 283.15 K to 323.15 K under 0.1 MPa. The experimental solubility order follows: 2-ME > 2-EE > 2-PE > 2-BE > MeOH > EtOH >  n -PrOH >  i -PrOH ≈  n -BuOH >  i -BuOH ≈ MeCN > EG. The UNIQUAC model, modified Apelblat model, NRTL model, Wilson model, Jouyban model and NRTL-SAC model equation were used to correlate of 1-HPE solubility, and the average 10 4 RMSD of them was 0.89, 1.21, 0.94, 4.72, 0.60 and 1.25, respectively. Furthermore, Hansen solubility parameters analysis (HSP) was used to evaluate the miscibility of 1-HPE in the selected solvents. Hirshfeld surface (HS) analysis was performed to discuss the electrostatic features and the patterns of intermolecular interactions of 1-HPE. Thermodynamic properties (Δ mix G , Δ mix S , Δ mix H , Δ dis G , Δ dis S , Δ dis H ) were calculated by the UNIQUAC model. The calculated results indicated that the dissolution and mixing process of 1-HPE in the mono-solvents selected in this work was spontaneous and entropy increment.

The remarkable structural comparison between two-dimensional and three-dimensional of 4, 4′-trimethylenedipyridine/1, 3, 5-trifluoro-2, 4, 6-triiodobenzene co-crystal

Jian He,Aisen Li,Yanchun Tao,Ning Chu,Zhixiang Wang,Shuping Xu,Jing Wang,Houyu Zhang,Jingsheng Yu,Weiqing Xu

A two-dimensional (2D) co-crystal composed of 1, 3, 5-trifluoro-2, 4, 6-triiodobenzene and 4, 4′-trimethylenedipyridine via halogen bonding (I···N) was obtained on highly-oriented pyrolytic graphite , and was characterized by scanning tunnelling microscope supplemented by the density functional theory calculation. Its special structure at the interface was further compared with its three-dimensional (3D) co-crystal structure. No orderly structures were observed when Au (111) was applied. The 2D co-crystal grown on the interface is significantly different from the 3D co-crystal. This study is of vital significance in understanding the growth mechanisms of 2D functional co-crystals.

Moisture-sensitive metal–organic framework constructed from cobalt and 4-(4-pyridyl) benzoic acid for dispersive solid-phase extraction of polycyclic aromatic hydrocarbons in apple

Fan Peng,Yuyan Tan,Shanshan Zhang,Xiaofang Yu,Huaixia Chen,Xueping Dang,Xiaolan Liu

A moisture-sensitive metal-organic framework Co II (pybz) 2 ·2DMF was synthesized and applied as the adsorbent of dispersive solid-phase extraction. The structure changed after water treatment due to the fact that two chelate carboxylate groups on the skeleton were transformed to monodentate because of the coordination of water molecules. The material showed good adsorption for fluorene, phenanthrene, fluoranthene, and pyrene in water because of the π–π conjugation and π-complexation effects. Coupled with high-performance liquid chromatography, a dispersive solid-phase extraction method of determining the content of fluorene, phenanthrene, fluoranthene, and pyrene in apple samples was established after optimizing the extraction conditions. Methanol containing 4% acetic acid was used as the effective eluent. The linearities were 0.5–1000 μg/kg for fluorene, phenanthrene and 5–1000 μg/kg for fluoranthene, pyrene. The limits of detection were 0.06–0.6 μg/kg, and the recoveries were 94.4–116.4%. The method has a high sensitivity for the determination of four polycyclic aromatic hydrocarbons in apple samples.

Gold nanoparticle-based detection of dopamine based on fluorescence resonance energy transfer between a 4-(4-dialkylaminostyryl)pyridinium derived fluorophore and citrate-capped gold nanoparticles

Peng Juanjuan,Zhou Na,Zhong Yang,Su Yaoquan,Zhao Lingzhi,Chang Young-Tae

A colorimetric/fluorometric dual-signal assay is described for the determination of dopamine (DA). A nanoprobe was obtained by linking a 4-(4-dialkylaminostyryl)pyridinium derived fluorophore to citrate-capped gold nanoparticles (AuNPs). The fluorescence of the fluorophore is quenched by the AuNPs via fluorescence resonance energy transfe. In the presence of DA, the catechol group of DA can absorb on the surface of AuNPs to induce aggregation, which is accompanied by a color change from red to blue. The yellow fluorescence of the fluorophore with excitation/emission maximum at 365/570 nm is recovered. The dual-signal detection allows the quantitative analysis of DA within 300 μM by the colorimetric method and 80 μM by the fluorometric method. The detection limits for the colorimetric/fluorometric methods are 1.85 μM and 0.29 μM, respectively. Quantitative determination of DA in spiked urine samples was successfully demonstrated, with recoveries ranging from 98.2 to 106.0%. A colorimetric/fluorometric dual-signal assay is described for the determination of dopamine by linking a fluorophore to gold nanoparticles. The dopamine causes aggregation of the nanoparticles to induce color change, which is followed by the recovery of the fluorescence.

Anti-Inflammatory Activity of 4-(4-(Heptyloxy)phenyl)-2,4-dihydro-3H-1,2,4-triazol-3-one via Repression of MAPK/NF-κB Signaling Pathways in β-Amyloid-Induced Alzheimer’s Disease Models

Fengmao An,Xinran Xuan,Zheng Liu,Ming Bian,Qingkun Shen,Zheshan Quan,Guowei Zhang,Chengxi Wei

Alzheimer’s disease (AD) is a major neurodegenerative disease, but so far, it can only be treated symptomatically rather than changing the process of the disease. Recently, triazoles and their derivatives have been shown to have potential for the treatment of AD. In this study, the neuroprotective effects of 4-(4-(heptyloxy)phenyl)-2,4-dihydro-3H-1,2,4-triazol-3-one (W112) against β-amyloid (Aβ)-induced AD pathology and its possible mechanism were explored both in vitro and in vivo. The results showed that W112 exhibits a neuroprotective role against Aβ-induced cytotoxicity in PC12 cells and improves the learning and memory abilities of Aβ-induced AD-like rats. In addition, the assays of the protein expression revealed that W112 reversed tau hyperphosphorylation and reduced the production of proinflammatory cytokines, tumor necrosis factor-α and interleukin-6, both in vitro and in vivo studies. Further study indicated that the regulation of mitogen-activated protein kinase/nuclear factor-κB pathways played a key role in mediating the neuroprotective effects of W112 against AD-like pathology. W112 may become a potential drug for AD intervention.Keywords:triazoles;Alzheimer’s disease;amyloid beta-peptides;neuroinflammation;mitogen-activated protein kinase/NF-kappa B signaling pathways

Catalytic debromination of 2, 2′, 4, 4′ – Tetrabromodiphenyl ether by low-cost mechanochemically synthesized graphite-doped oxalated Fe/Ni bimetals: Enhanced generation of adsorbed atomic H and secondary risk control

Kuang Wang,Zhanqiang Fang

In this work, a cost-effective ball-milling technique was employed to synthesize submicron oxalated zero-valent iron co-doped with graphite and nickel (G@Fe OX bm /Ni), aiming to enhance the removal efficiency of the recalcitrant pollutant 2, 2′, 4, 4′ – tetrabromodiphenyl ether (BDE-47) while minimizing secondary risks. The incorporation of graphite significantly improved the debromination efficiency of BDE-47, with a rate constant of 0.26 day −1 in a tetrahydrofuran/water system, which represents a 59.88 % increase over the oxalated zerovalent Fe/Ni without graphite (0.16 day −1 ). The determination of Ni leaching showed that no nickel ions were detected post-reaction over a broad pH range (3–11). Moreover, the reactivity of G@Fe OX bm /Ni was largely unaffected across the pH range (0.26–0.49 day −1 ), exhibiting excellent resistance to acidic and alkaline conditions. In both ultrapure water and real groundwater matrices, the degradation rate constants for BDE-47 increased to 2.98 day −1 and 0.79 day −1 , respectively, achieving debromination yields of 97.86 % and 50.18 % for the final product, diphenyl ether. Based on the established degradation pathway and electrochemical analysis, the debromination of BDE-47 follows a catalytic debromination and hydrogenation process by adsorbed atomic hydrogen (H* ADS ). The graphite doping enhanced the debromination of BDE-47 by increasing the production of H* ADS . The adsorption effect of graphite on metal ions effectively controlled secondary pollution and improved the material’s tolerance to acidic and alkaline environments. This work offers an efficient method for the degradation of low brominated diphenyl ether pollutants at a low cost and without secondary risks.

Low-dielectric-constant aromatic homopolyimide and copolyimide derived from pyromellitic dianhydride, 4,4′-oxydianiline, 2,2-bis[4-(4-aminephenoxy)phenyl]propane, 1,4-bis(4-aminophenoxy)benzene, or 1,3-bis(4-aminophenoxy)benzene

Guorong Qiu,Wenshi Ma,Yuanqi Jiao,Li Wu

Low-dielectric-constant aromatics, homopolyimide and copolyimide, were introduced. Homopolyimides were prepared by pyromellitic dianhydride (PMDA) as an anhydride monomer and 4,4′-oxydianiline (ODA), 2,2-bis[4-(4-aminephenoxy)phenyl]propane, 1,4-bis(4-aminophenoxy)benzene, or 1,3-bis(4-aminophenoxy)benzene as an amine monomer. The copolyimides were prepared with PMDA as an anhydride monomer, ODA as an amine monomer with the addition of 2,2-bis[4-(4-aminephenoxy)phenyl]propane, 1,4-bis(4-aminophenoxy)benzene, or 1,3-bis(4-aminophenoxy)benzene as another amine monomer. The polyimides were well characterized by Fourier transform infrared spectroscopy, thermogravimetric analysis, thermomechanical analysis, dielectric measurements, and tensile testing. The homopolyimide and copolyimides showed lower dielectric constants than the homopolyimide formed by ODA and PMDA. The results also indicate that the interchain distance, the quantities of phenyl ether, and the position of the substitute are factors that not only affected the thermal performance of polyimide by improving the molecular flexibility but also reduced the dielectric constant of polyimide by increasing the free volume of the molecular chain and decreasing the polarization points per unit volume. © 2019 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2019 , 136 , 47405.