Solvothermal synthesis of well-defined TiO(2) mesoporous nanotubes with enhanced photocatalytic activity

High efficiency TiO(2) photocatalyst in porous nanotubes were prepared by solvothermal alcoholysis of TiOSO(4) in the presence of carbon nanotube template.     

Preparation and application of solid-phase microextraction fiber based on molecularly imprinted polymer for determination of anabolic steroids in complicated samples

A relatively selective, chemically and physically robust SPME fiber was developed in a simple way with testosterone-imprinted polymer, and then directly coupled with gas chromatography-mass spectrometry (GC-MS) for selective extraction and analysis of anabolic steroids. The factors influencing polymerization (i.e., cross-linker, polymerization solvent, polymerization time) were optimized in detail and the polymer was characterized by scanning electron microscope, infrared spectrometer and thermogravimetric analyzer. Furthermore, the extraction performance of the MIP-coated SPME fibers such as extraction ability and selectivity was evaluated. Moreover, the interaction mode between target analytes and fiber coating was deducted. Finally, the method for extraction and determination of androsterone, stanolone, androstenedione and methyltestosterone by the homemade MIP-coated SPME fibers with GC-MS was obtained. It was applied to the simultaneous analysis of four anabolic steroids in the spiked human urine with the satisfactory recoveries.     

Xylocarpanoids A and B, unique C28 skeleton limonoids from Xylocarpus granatum

One novel tetranortriterpenoid derivative, xylocarponoid A, representing the first example of C28 skeleton limonoid, was isolated from the seeds of the Chinese mangrove, Xylocarpus granatum. Its C-1′-epimer, xylocarponoid B, was formed in CDCl₃. Their structures were elucidated by extensive spectroscopic analysis. A plausible biosynthetic pathway of xylocarponoid A was proposed.     

H-shaped oligothiophenes with low band gaps and amphoteric redox properties

H-shaped bridged oligothiophenes HT-1 and HT-2 were synthesized by two different approaches. Different from normal oligothiophenes, HT-1 and HT-2 showed low band gaps and amphoteric redox behaviors due to intramolecular charge transfer, which is further supported by time-dependent DFT calculations.     

胶束电动毛细管色谱-电喷雾质谱联用法同时测定妇宁栓中的5种有效成分

应用胶束电动毛细管色谱-电喷雾电离质谱联用法同时测定了妇宁栓中的小檗碱、巴马汀、苦参碱、儿茶素和黄芩苷5种主要有效成分的含量。在未涂层石英毛细管柱(80 cm×50 μm)中,以40 mmol/L月桂酸-100 mmol/L氨水溶液(含25%的乙腈,pH 9.5)为缓冲液,分离电压为25.0 kV,各组分在16 min内得到完全分离。电喷雾质谱检测时采用50%异丙醇水溶液(含3 mmol/L乙酸)为鞘液。结果表明,小檗碱、巴马汀、苦参碱、儿茶素、黄芩苷的线性范围分别为0.03～15、0.05～15、0.2～250、1.5～300和2.0～500 mg/L,检出限分别为0.01、0.02、0.05、0.5、0.6 mg/L。5种组分的加标回收率为94.0%～104.0%,相对标准偏差(RSD)在0.3%～3.2%之间。该法简便、快速、准确,重现性好,可用于妇宁栓中小檗碱、巴马汀、苦参碱、儿茶素、黄芩苷含量的同时测定。     

核壳结构Ziegler-Natta复合催化剂的制备及其乙烯聚合

采用溶胶-凝胶法,将聚(苯乙烯-co-丙烯酸)(PSA)膜材料和氯化镁的复合物包覆在以硅胶为载体的TiCl3催化剂上,负载TiCl4后制得Ziegler-Natta复合催化剂.采用红外光谱、激光粒度仪和扫描电镜对催化剂进行了表征,结果表明该复合催化剂呈核壳结构.同时,考察了复合催化剂中膜的厚度和反应中的氢气含量对催化剂的聚合活性和聚乙烯性能的影响,实验发现,膜厚约为3μm的核壳结构复合催化剂活性良好,其具有带诱导期的平稳型动力学曲线;膜厚1.5μm的复合催化剂的活性接近于实验所用的以硅胶为载体的TiCl3催化剂,且其具有相似的衰减型动力学曲线.研究同时表明,不同的膜厚能够调节复合催化剂的氢调性能及所得聚乙烯的分子量分布.     

Synthesis and Photophysics of Novel Soluble Polymeric Zn Metal Complex Based on Bis(8-hydroxyquinoline) Groups with Benzene Unit

A novel ligand: 2,2′‐(1,3‐phenylenedivinylene)bis‐8‐hydroxyquinoline (m‐B8QPH) ( 4 ) and the corresponding polymeric metal complex Zn ( m‐B8QPH ) ( 5 ) were designed and synthesized in a convenient way. The luminescence properties of the compounds Zn ( m‐B8QPH ) ( 5 ) and Zn(p‐B8QPH) ( 9 ) were investigated by UV‐vis and fluorescence spectra in DMF at room temperature. The experimental results showed that the polymeric complexes 5 and 9 emitted yellow luminescence at 578 and 554 nm in DMF solution. The polymeric complex 5 has demonstrated good solubility in common organic solvents and good thermal stability with high T_g: 261°C. Furthermore, the molecular interactions of 5 with fullerene (C₆₀) and fulleropyrrolidine containing 3,5‐bis(trifluoromethyl)benzene ( 11 ) were also investigated, which indicated the metal dye 5 can be used as new fluorescent probe.     

Extraction of Co-Products from Biomass: Example of Thermal Degradation of Silymarin Compounds in Subcritical Water

In an effort to increase revenues from a given feedstock, valuable co-products could be extracted prior to biochemical or thermochemical conversion with subcritical water. Although subcritical water shows significant promise in replacing organic solvents as an extraction solvent, compound degradation has been observed at elevated extraction temperatures. First order thermal degradation kinetics from a model system, silymarin extracted from Silybum marianum, in water at pH 5.1 and 100, 120, 140, and 160 °C were investigated. Water pressure was maintained slightly above its vapor pressure. Silymarin is a mixture of taxifolin, silichristin, silidianin, silibinin, and isosilibinin. The degradation rate constants ranged from 0.0104 min⁻¹ at 100 °C for silichristin to a maximum of 0.0840 min⁻¹ at 160 °C for silybin B. Half-lives, calculated from the rate constants, ranged from a low of 6.2 min at 160 °C to a high of 58.3 min at 100 °C, both for silichristin. The respective activation energies for the compounds ranged from 37.2 kJ/gmole for silidianin to 45.2 kJ/gmole for silichristin. In extracting the silymarin with pure ethanol at 140 °C, no degradation was observed. However, when extracting with ethanol/water mixtures at and 140 °C, degradation increased exponentially as the concentration of water increased. An erratum to this article can be found at     

刚性配体2,2-联吡啶诱导的双咪唑金属超分子配合物的合成与晶体结构

合成了3种新的超分子配合物[Cd(H2biim)(2,2'-bipy)(NO3)2] (1), [Cu(H2biim)(2,2'-bipy)(H2O)](NO3)2 (2)和[Zn(H2biim)(2,2'-bipy)(H2O)](NO3)2 (3) (H2biim＝双咪唑; 2,2'-bipy＝2,2'-联吡啶), 并通过X射线单晶衍射测定了其结构. 配合物1～3均为单斜晶系, 属于P2(1)/c空间群, 在1中, Cd(II)为六配位, 它与双咪唑的2个氮原子, 联吡啶的2个氮原子和2个硝酸根的2个氧原子配位. 在2和3中, Cu(II)和Zn(II)均为五配位的, 它们与双咪唑的2个氮原子、2,2'-联吡啶的两个氮原子和一个水分子配位. 1～3的对称单元均通过双咪唑、硝酸根和水之间形成的氢键R21(7), R21(4) 和R44(18)构筑了1D链状超分子.     

Synthesis of new 2-aryl-6-styryl-2,3-dihydropyridin-4(1H)-one derivatives from curcuminoids

Series of new 2-aryl-6-styryl-2,3-dihydropyridin-4(1H)-one derivatives were synthesized in acceptable to good yields by treatment of the curcuminoids with aqueous ammonia,the mechanism was proposed.By modification of the primary products,total 13 new compounds were obtained.The structures of all products were elucidated by spectroscopy analysis including HR-MS,~1H NMR and ~(13)C NMR.