167 resultados para 2-Bromo-1,4-naphthoquinone
Resumo:
Two 3d-4f heterometallic compounds of p-tert-butylsulfinylcalix[4] arene were synthesized by the solvothermal method and characterized by some hinged double-dumbbell-like subunits in which two perpendicular dumbbell entities were constructed by an in-between isosceles triangle Mn(II)Ln(2)(III), and two tail-to-tail calixarene molecules, and hinged by the lanthanide-sulfinyl group bonding. The magnetic properties of the title compounds were examined.
Resumo:
Linear low density polyethylene (LLDPE) was functionalized with 2-acrylamido-2-methyl-1-propanesulfonic acid (AMPS) by using -ray pre-irradiation in air in a twin-screw extruder. Fourier-transformed infrared spectroscopy (FT-IR) and electron spectroscopy for chemical analysis (ESCA) were used to characterize the formation of LLDPE-g-AMPS copolymers. The content of AMPS in LLDPE-g-AMPS was determined by using element analysis instrument. The effects of concentrations of monomer, reaction temperature and pre-irradiation dose on degree of grafting were investigated. The critical surface tension of LLDPE-g-AMPS was measured by using contact angle method. The influences of the degree of grafting on crystallization properties were studied by using DSC. Compared with neat LLDPE, the crystallization temperature increased about 4C, and crystallinity decreased with increasing degree of grafting. Crystallization rates of grafted LLDPE were faster than that of plain LLDPE at the same crystallization temperature.
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The interfaces formed between copper-hexadecafluoro-phthalocyanine (F16CuPc) and 2,5-bis(4-biphenylyl) bithiophene (BP2T) were examined using photoemission and inverse photoemission spectroscopy. It is observed that in F16CuPc/BP2T the heterojunction is characterized by band bending in both materials, while in BP2T/F16CuPc the band bending is confined in BP2T only. The combination of the band bending and finite Debye lengths provides an explanation to the observed ambipolar behavior of the organic thin film transistors based on such heterojunctions.
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A series of new 1,1'-bi-2-naphthol (BINOL) derived ligands, 3-[6-(hydroxymethyl)pyridin-2-yl]-BINOLs or 3,3'-bis[6(hydroxymethyl)pyridin-2-yl]-BINOLs, bearing one or two chiral pyridinylmetlianols attached to a binaphthyl skeleton, have been synthesized using the Suzuki cross-coupling reaction. The resulting compounds have been used as ligands in the enantioselective addition of diethylzinc to aldehydes; the products were obtained with up to 96% ee.
Resumo:
采用Nd(P507)3 LiBu AlEt3和AlEt3 VCl3两种催化剂体系分别合成了两种分子量与反式1,4单元结构含量不同的反式1,4 聚丁二烯样品(TPBD)。用DSC方法不仅研究了两样品六方相晶体的非等温结晶过程,同时还对单斜相结晶的非等温动力学过程进行了研究。Avrami方程分析显示,在低结晶度下TPBD六方相和单斜相的结晶生长过程呈现热成核的三维球晶生长。研究表明:虽然Ozawa方程在较低温度下能描述TPBD的六方相结构的实验数据,但不能完全描述在较高温度下六方相及单斜相非等温结晶过程,而用莫志深等建议的方程则能很好地描述TPBD六方相和单斜相非等温结晶过程。由Kissinger方程得到TPBD六方相和单斜相结晶的平均结晶活化能分别为-165.8kJ/mol和-220.5kJ/mol。
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一种1,4-丁二醇脱氢制备γ-丁内酯催化剂,其各组份重量百分比为:CuO48-55%;ZnO42-50%;Ce↓[2]O↓[3]2-3%。催化剂在1,4-丁二醇脱氢制备γ-丁内酯应用先在氢气气氛中还原活化,然后装入固定床反应器内,反应温度210-260℃,反应压力小于0.05MPa,液体空速0.1-0.7hr↑[-1]。本发明催化剂具有较高的活性,1,4-丁二醇转化率大于98%,γ-丁内酯选择性大于95%,催化剂中不含Cr的优点。
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用电化学方法研究了影响 1,4 二氢吡啶类衍生物中 1,4 二氢吡啶的电化学行为的因素。结果表明 ,有机溶剂的偶极矩对 1,4 二氢吡啶电化学行为的影响最大 ,有机溶剂中含水量也有很大的影响 ,1,4 二氢吡啶上取代基的吸电子性也在一定程度上影响它的电化学性能
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Novel hole-transporting molecules containing 1,4-bis(carbazolyl)benzene as a central unit and different numbers of diphenylamine moieties as the peripheral groups have been synthesized and characterized. These compounds are thermally stable with high glass transition temperatures of 141-157 degreesC and exhibit chemically reversible redox processes. Their amorphous state stability and hole transport properties can be significantly improved by increasing the number of diphenylamine moieties in the outer part and by controlling the symmetry of the carbazole-based molecules. These compounds can be used as good hole-tran sporting materials for organic electroluminescent (EL) devices. The device performance based on tri- and tetra-substituted carbazole derivatives is comparable to that of a typical 4,4'-bis[N-(1-naphthyl)-N-phenylamino] biphenyl (NPB)-based device.
Resumo:
一种1,4丁二醇脱氢制备γ-丁内酯催化剂其组成为:CuO 30-70% ZnO 15-40% Al↓[2]O↓[3] 2-24%助剂0.001-9%,其中助剂由BaO、Pd两种物质中的至少一种制备而成。该催化剂在氢气气氛中还原活化,然后装入固定床反应器内,反应温度200-260℃,反应压力小于0.05MPa,液化空速0.1-1.2hr↑[-1]下应用。本发明具有较高的活性和选择性,1,4-丁二醇转化率100%,γ-丁内酯选择性大于96%,催化剂中不含Cr的优点。
Resumo:
A facile, mild and rapid solid phase synthetic route free of column chromatographic purification to the synthesis of soluble monodisperse long-chain oligo(1,4-phenyleneethynylene)s is presented.
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A series of polyimides (PIs) based on 2,3,3',4'-benzophenonetetracarboxylic dianhydride (2,3,3',4'-BTDA) and 3,3',4,4'-BTDA were prepared by the conventional two-step process. The properties of the 2,3,3',4'-BTDA based polyimides were compared with those of polyimides prepared from 3,3',4,4'-BTDA. It was found that PIs from 2,3,3,4'-BTDA have higher glass transition temperature and better solubility without sacrificing their thermal properties. Furthermore the theological properties of PMR-15 type polyimide resins based on 2,3,3',4'-BTDA showed lower melt viscosity and wider melt flow region (flow window) compared with those from 3,3',4,4'-BTDA. The structure-property relations resulted from isomerism were discussed.
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Reaction of YbI2 with two equivalents of cyclopentylindenyl lithium (C5H9C9H6Li) affords ytterbium(II) substituted indenyl complex (C5H9C9H6)(2)Yb(THF)(2) (1) which shows high activity to ring-opening polymerization (ROP) of lactones. The reaction between YbI2 and cyclopentylcyclopentadienyl sodium (C5H9C5H4Na) gives complex [(C5H9C5H4)(2)Yb(THF)](2)O-2 (2) in the presence of a trace amount of O-2, the molecular structure of which comprises two (C5H9C5H4)(2)Yb(THF) bridged by an asymmetric O-2 unit. The O-2 unit and ytterbium atoms define a plane that contains a C-i symmetry center.
Resumo:
经由配位聚合反应 ,合成了八羟基喹啉锌和 1 ,4 二乙烯基苯的交替共聚物。所合成的聚合物通过元素分析和红外光谱进行了表征。在 36 5nm的紫外光照射下 ,聚合物呈现强的橘红色发光 ,在乙氰溶液中的最大发光峰位在 5 71nm。热失重分析表明 ,这种含Znq2 的聚合物具有稳定的热力学性质 ,热失重 5 %的温度大于 4 39℃。这种聚合物的电致发光性质正在研究中
Resumo:
The cyclization of cis-1,4 polybutadiene in various solvents (mesitylene,xylene, toluene,benzene and cyclohexane) with the catalyst composed of CH2=CHCH2Cl-AlEt2Cl was studied. The infrared spectra of the cyclized products were investigated. It was shown that the products produced in cyclohexane and mesitylene have infrared spectra identical with those of the original cis-1,4-polybutadiene and the products obtained in other aromatics have infrared spectra different from each other and distinguishing with those of the parent cis-1,4 polybutadiene. The analyses of infrared spectra came to the conclusion that the molecules of aromatic solvent participate in cyclization of cis-1,4 polybutadiene at the given condition. A possible reaction scheme involving an electrophilic substitution of carbonium ions for Ar-H of aromatic solvents was proposed. Some experimental facts were explained with great satisfaction on the basis of the above mechanism.