Photoreactions of 1,2,4,5-benzenetetracarbonitrile with arylethenes—photo- olefin dimerization-aromatic substitution reactions

Irradiation of 1,2,4,5-tetracyanobenzene (TCNB) with styrene derivatives 1-4, respectively, leads to a photochemical olefin dimerization-aromatic substitution reaction to give the corresponding (2,4,5-tricyanophenyl)tetralin derivative (8, 12, 16, 17, and 20) as the main product. Further irradiation of the primary product with alkene results in substitution of the meta-CN group by another phenyltetralinyl to give the corresponding 4:1 (alkene-TCNB) product. According to the effect of the codonor (biphenyl) and salt (magnesium perchlorate) on reaction rate, the result of photoinduced reactions of TCNB with tetralin (6) and 1-phenyltetralin (7) and analysis of the known kinetic data for relevant processes in the cyanoarene-alkene reactions, the mechanism for the formation of the olefin dimerization-aromatic substitution products (such as 8) is proposed to involve radical pair combination of the alkene cyclodimer radical (the corresponding 4-phenyl-1-tetralinyl radical) with TCNB⁻ followed by expulsion of a CN⁻. Photoreactions of TCNB with the alkene photocyclodimer (1-phenyltetralin) may also make minor contributions. Photoinduced reaction of TCNB with 1-phenylcyclohexene (5) takes a different pathway from 1-4 to afford the 1:1 (5-TCNB) primary product 21 by deprotonation of 5⁺ and radical pair combination with TCNB⁻ followed by elimination of HCN.     

低价钛促进的1,2-二氢喹唑啉-4(3H)-酮的合成

喹唑啉-4(3H)-酮是一类生物碱,取代喹唑啉-4(3H)-酮具有广泛的药理学活性．因而对其合成方法和合成新型喹唑啉-4(3H)-酮的衍生物的研究已成为热点．低价钛试剂是一种还原偶联试剂,它能引起醛酮的还原偶联生成烯烃,还能引起其它官能团的还原偶联反应,该反应已应用于天然产物和一些碳环化合物的合成,而用于杂环化合物的合成研究报道较少．本文报道低价钛试剂(TiCl4-Zn体系)促进的1,2-二氢喹唑啉-4(3H)-酮的合成。     

双核Cu(Ⅱ)-2，4-二羟基苯甲醛缩邻氨基苯甲酸Schiff碱配合物的合成、表征和晶体结构

The novel dinuclear copper(Ⅱ) complex with with N-(2，4-dihydroxybenzalidene)-o-aminobenzoic acid ligand， [Cu(C₁₄H₉NO₄)]₂·2H₂O， has been synthesized and characterized by elemental analysis， IR， UV-Vis and thermal analysis. Its crystal structure was determined by single crystal X-ray diffraction techniques. The crystal belongs to monoclinic with space group P2₁/c. The cell parameters are: a=0.82510(11)nm， b=0.68870(9)nm， c=2.3007(3)nm， β=100.847(2)°， V=1.2840(3)nm³， Z=2，D_c=1.742Mg·m^-3， μ(Mo Kα)=1.723mm^-1， F(000)=684. The structure was refined to final R₁=0.0267， wR₂=0.0735. The complex molecule structure has dinuclear centrosymmetric dimeric structure in which a planar Cu₂O₂ core features. The ligand N-(2，4-dihydroxybenzalidene)-o-aminobenzoic acid dianion is μ₂-tridentate， chelating one copper(Ⅱ) ion via one nitro-gen， one hydroxy oxygen atom and one carboxylate oxygen atom， and the hydroxy oxygen atom simultaneously co-ordinates to the other copper(Ⅱ) ion of the dimer. In the structure the copper(Ⅱ) ion rendered four-coordination in a distorted square-planar geometry structure. CCDC: 212695.     

An Unexpected Discovery in the Willgerodt-Kindler Reaction of Acetophenone——the Formation of the 4-（Benzoylthiocarbonyl）morpholine

The Willgerodt-Kindler reaction of acetophenone was studied.Apart from the normal product 4-(benzylthio-carbonyl)morpholine,another product 4-(benzoylthiocarbonyl)morpholine was obtained unexpectedly.The struc-ture of the latter was confirmed by IR,~1H NMR spectra and X-ray diffraction analysis.The mechanism of the reac-tion was discussed.     

3-硫代甲酰基中氮茚(硫醛)与碘化1,2-及1,4-二甲基吡啶鎓盐的反应

用改进的Vilsmeier反应由3位未取代的中氮茚合成了一系列3-硫代甲酰基中氮茚(硫醛),对其在甲醇溶液中哌啶催化下与碘化1,2-二甲基吡啶鎓盐及碘化1,4-二甲基吡啶鎓盐的缩合反应进行研究,高收率地合成了相应含中氮茚环的二甲川菁,产物结构经元素分析、红外光谱、¹H谱及质谱确证,并测定了其在固态下的荧光性质.结果表明,所有的化合物发射波长都在400nm以上,有希望成为发光材料.     

卟吩垂直激发态的理论研究方法的比较

运用TDDFT、ZINDO、INDO/S三种量子化学理论方法,对卟吩的单线垂直激发态进行了理论计算与归属研究.研究发现,对于卟吩类大分子而言, ZINDO和INDO/S方法对研究Q带和B带等特征的低能量激发态具有足够的精度,且对高能带也能给出定性的解释,可以用于更大的生物发色团分子的垂直激发态的理论研究.     

Electrochemical study of PEDOT-PSS-MDB-modified electrode and its electrocatalytic sensing of hydrogen peroxide

A method to fabricate poly(3,4-ethylene dioxythiophene)-poly(4-styrene sulfonate)-Meldola Blue (PEDOT-PSS-MDB)-modified electrodes had been disclosed. Firstly, the PEDOT-PSS-film-modified electrode was electrochemically prepared. Then, the PEDOT-PSS was treated as a matrix to immobilize electroactive mediator, Meldola Blue (MDB), by means of an electrostatic interaction to form the proposed film, PEDOT-PSS-MDB. Electrochemical properties of the proposed film exhibited surface confinement and pH dependence. The PEDOT-PSS-MDB electrode could electrocatalytically reduce hydrogen peroxide (H₂O₂) with a low overpotential and showed a linear response to H₂O₂ in the concentration range of 5 to 120 μM, detection limit of 0.1 μM, and sensitivity of 353.9 μA mM⁻¹ cm⁻² (S/N = 3). By comparison, the electrocatalytic activity of PEDOT-PSS-MDB electrode was found superior to that of PEDOT-PSS and MDB-PSS electrodes. It also has competitive potential as compared with other mediators, through the use of HRP to determine H₂O₂. Moreover, the potential interferents such as ascorbic acid, dopamine, uric acid, and glucose were also studied for H₂O₂ determination by the proposed film.     

单一手性一价铜配位聚合物:晶体结构,荧光,SHG响应及介电性质(英文)

<正>Under hydrothermal conditions,homochiral ligand(4aR,8aR)-2,3-di(thiophen-2-yl)-decahydroquinoxaline (DTDCQ) reacted with CuBr to give 1D helical chain complexes[(DTHHQ)CuBr]_n(1).Single crystal X-ray determination shows that compound 1 crystallize in chiral space groups P2_12_12_1 and the experimental result indicated that 1 has SHG(second harmonic generation) active with approximate responses 0.4 times that of urea,Fluorescent analysis showed it exhibits one intense emission band at 377 nm when the exciting radiation was set at 340 nm. Dielectric constant of compound 1 were measured at different frequencies at room temperature.     

含硫套索冠醚的合成

将二氮杂１８－冠－６的乙腈溶液分别与２－氯乙基烷基硫醚、２－氯乙基烯丙基硫醚、［２－（２－ｒ氯乙基）硫乙基］烷基硫醚在无水碳酸钾存在下反应制得５种新型侧链上含硫原子的双臂套索冠醚和５种新型单臂套索冠醚。它们的收率分别为３７％－７２％和１３％－３７％。此法比其它制备单臂套索冠醚的方法操作简单。     

Effects of metal salts on the thermal decomposition of edta-gel precursors for ferroelectric ceramic powders

Raw chemicals such as metal nitrates and chlorides were found to affect the thermal decomposition behaviour of EDTA-gel precursors used for the production of ceramic powders. Fine, homogeneous ceramic powders were produced from nitrate solutions while chlorides gave segregated phases. In studies on the production of lead zirconate titanate (PZT) using chlorides, the segregation and loss of lead was observed and shown to be caused by the formation and evaporation of PbCl₂. Thermal analysis (DTA/TG) quantitatively proved the suggested reaction mechanism for this phase segregation. Crystallization of the desired perovskite phase of lead zirconate titanate (PZT) and barium titanate (BT) initiated at temperatures as low as 250°C in the nitrate-EDTA precursors. Water of crystallization and formation of BaCO₃ in the barium titanate precursor were suggested to account for differences in the observed decompositional behaviours of the BT and PZT precursors.