噻吩乙醇的合成研究

提出了可工业化的噻吩乙醇合成方法，并详细地讨论了降低副产特生成的途径。对溴化和格氏化条件进行了研究。     

Mannich反应合成2-噻吩甲胺

2-噻吩甲胺是一种重要的医药中间体,主要用于合成阿佐塞米(Azosemide)和氯苯磺酸西尼铵(Thenium Closilate)。以噻吩、甲醛、氯化铵为原料,通过Mannich反应合成出2-噻吩甲胺。通过考察条件得出:在反应温度为60～65℃,时间40～50min,噻吩:甲醛:氯化铵=1∶3∶3(mol)时,选择性最高可达35%;Mannich反应后加入甲醇反应,使得反应选择性提高到57%;2-噻吩甲胺粗品先成为盐酸盐再精馏,产品纯度达到99%。     

气相色谱-火焰光度法测定苯中微量环丁砜和噻吩

建立了气相色谱-火焰光度法测定苯中微量环丁砜和噻吩的方法,对色谱条件进行了优化,定量方法采用外标法。该方法的加标回收率为114%～136%;相对标准偏差（RSD）不大于7%。测定苯样品中微量环丁砜和噻吩具有灵敏度高、重现性好和可靠性高等优点。     

The Mechanism of HDS Catalysis

The mechanism of heterogeneous catalytic reactions is much more difficult to elucidate than that of homogeneous systems. Despite the facilities provided by physical methods for investigating the surface of solids, obtaining detailed information on the structure of the active component in real heterogeneous catalysts presents difficulties due to the nonuniform chemical composition of the surface species. Some of these surface species are totally inactive in catalysis, and others can catalyze the given chemical reaction by different pathways and according to different mechanisms. This results in a change of selectivity to the desired product and the appearance of intermediates and reaction by-products. Furthermore, the effect of the reaction medium on the catalyst gains importance during a catalytic process when, at high temperature and pressure, one type of surface species is transformed into another, thus changing the mechanism and direction of the catalyzed reaction.

     

Unusual band-gap migration of N-alkylcarbazole-thiophene derivative

The 9-heptyl-3,6-di(thiophen-2-yl)-9H-carbazole (BTC-C7) monomer shows unusual electronic properties during electropolymerization process, we describe the possibility of electrosynthesis of oligomers of different chain length. What is extraordinary about these systems is that their band-gap size is the same, irrespective of the number of repeat units in the oligomer. We compared band-gap width for different oligomers using absorption spectroscopy, cyclic voltammperometry. Analysis of this data suggests that the observed constant band-gap width feature is due to simultaneous, and equipollent change of the energy of HOMO and LUMO orbitals across the series of oligomers being considered.     

Effect of the fluorine-addition order on the hydrodesulfurization activity of fluorinated NiW/Al2O3 catalysts

Fluorinated NiW/Al₂O₃ catalysts with different orders of fluorine addition have been prepared, tested for hydrodesulfurization (HDS) of thiophene, and characterized using nitric oxide chemisorption and temperature-programmed sulfidation. The catalyst surface area has been affected by fluorine addition but not by the order of fluorination. The fluorine addition-order does not affect the amount of fluorine retained in the catalysts after the calcination and the reaction steps, either. On the other hand, the order of fluorine addition changes the dispersion of the nickel and the tungsten species, incorporation of nickel with the tungsten edge sites, and consequently the HDS activity of the catalysts. The catalyst fluorinated in the last step, i.e., after addition of both tungsten and nickel, shows the highest activity in thiophene HDS, which is supported by other experimental results indicating the most nitric oxide chemisorption and the largest incorporation of nickel with the tungsten species. Accordingly, enhancement of the catalyst activity by fluorination is due to the repartition of the metal species rather than to partial solubilization of alumina in the fluorine-addition step.     

The effect of thiophene sequence separation on air-stable organic thin-film transistor materials

The relationship between thiophene sequences and organic thin-film transistor (OTFT) characteristics was studied to determine their effect on ionization potential, molecular orientation, and air stability. Two types of molecular structures were used: continuous sequence and divided sequence thiophenes. The length of thiophene sequence did not affect FET characteristics but did affect ionic potential and air stability. Furthermore, materials with divided thiophene sequences showed no change in OTFT characteristics when exposed to air. These results suggest that separation of thiophene sequences can improve air stability, which is a problem of thiophene-based materials.     

Theoretical investigation of the interaction between aromatic sulfur compounds and [BMIM]+[FeCl4]− ionic liquid in desulfurization: A novel charge transfer mechanism

In this work, interaction nature between a group of aromatic sulfur compounds and [BMIM]⁺[FeCl₄]⁻ have been investigated by density functional theory (DFT). A coordination structure is found to be critical to the mechanism of extractive desulfurization. Interaction energy and extractive selectivity follow the order: thiophene (TH) < dibenzothiophene (DBT) ≈ benzothiophene (BT). Alkylation of TH or BT (e.g. 3-methylthiophene, and 3-methylbenzothiophene) leads to a stronger interaction with ionic liquid, but steric hindrance effects of some alkylic derivatives (e.g. 2,7-dimethylbenzothiophene) lead to a weaker interaction with ionic liquid. The mechanism of extractive desulfurization is attributed to the charge transfer effect. During extractive desulfurization, electrons on aromatic sulfur compounds transfer into the Lewis part of ionic liquid, namely, [FeCl₄]⁻. Furthermore, it is better to consider the Lewis acidity of Fe-containing ionic liquid by the whole unit (such as [FeCl₄]⁻ and aromatic sulfur compounds (X)) rather than only Fe or S atom.     

Conjugated polythiophene/Ni doped ZnO hetero bilayer nanocomposite thin films: Its structural,optical and photoluminescence properties

In this study, synthesis and characterization of plasma polymerized Thiophene/ Nickel doped Zinc Oxide (PTNZO) bilayer nanocomposite films were carried out. Nickel doped zinc oxide (NZO) thin films were obtained by magnetron sputtering technique on glass substrates at 40 W Radio Frequency (RF) power. Plasma polymerized Thiophene (PT) thin films were deposited on the NZO thin films obtained on the glass substrate by Radio Frequency (RF) plasma polymerisation technique. X-Ray Diffraction (XRD), Scanning Electron Microscopy (SEM), FTIR and Photoluminescence (PL) analyzes were performed for the characterization of PTNZO hetero bilayer nanocomposite films. In the XRD spectra of PTNZO bilayer nanocomposite thin films, (002) planes were determined as the most basic peak, and it was determined that the intensity of this peak, changed depending on the RF power of polymer thin films. Optical properties of nanocomposite thin films such as transmittance, absorbance and optical band gap were determined by UV–Vis spectroscopy. Optical band gap for PTNZO nanocomposites were 2.72?eV, 2.34?eV, and 2.45?eV, respectively, with increasing RF power. For NZO thin films, this value is 3.12?eV. The optical band gaps calculated from the absorption and transmittance spectra obtained using UV–visible spectroscopy had a good compatibility with those of the optical band spectra calculated from the PL spectra. The tetragonal wurtzite structure of the NZO thin films was examined by SEM analysis. The grain size of NZO nanostructure was found to be approximately 59?nm.     

β-Selective C−H Arylation of Electron-Deficient Thiophenes,Pyrroles, and Furans

A general β-C−H arylation of electron-deficient thiophenes, pyrroles, and furans has been developed using ligand-modulated palladium catalyst. The use of a modified norbornene is crucial for reversing the conventional α-selectivity of these substrates. This method features good yields, high β-selectivity, and good tolerance of functional groups.