975 resultados para Aisberg-2-2004-1


Relevância:

100.00% 100.00%

Publicador:

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.

Relevância:

100.00% 100.00%

Publicador:

Resumo:

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.

Relevância:

100.00% 100.00%

Publicador:

Resumo:

The structure of the title compound, [Cu2Cl2(C12H10N2)](n), contains infinite CuCl staircase-like chains, which lie about inversion centres. The trans-1,2-di-4-pyrid-ylethyl-ene mol-ecules also lie about inversion centres and connect the CuCl chains through Cu-N coordination bonds into a two-dimensional organic-inorganic hybrid network. The planar sheets are stacked along the c axis and associated through weak C-H center dot center dot center dot Cl inter-actions. The results show a reliable structural motif with controllable separation of the CuCl chains by variation of the length of the ligand.

Relevância:

100.00% 100.00%

Publicador:

Resumo:

2-(2-Hydroxyphenyl)-5-phenyl-1,3,4-oxadiazole 1 and 2,5-bis(2-hydroxyphenyl)-1,3,4-oxadiazole 2 were used as anion fluorescent and colorimetric chemosensors with high selectivity for H2PO4- and F- over Cl-, while 2 can even distinguish H2PO4- from F-. (C) 2002 Elsevier Science Ltd. All rights reserved.

Relevância:

100.00% 100.00%

Publicador:

Resumo:

由 5-(2-乙酰基-1-甲硫基-3-羰基-亚丁基)-丙二酸亚异丙酯 (1)与邻苯二胺及乙酸镍()经一步反应合成了3{1-[2-( -3-羟基-1-甲基-2-亚丁烯氨基)-苯亚氨基 ]-乙基} 4-甲硫基-2,4-戊二烯-2-醇(3)的不对称四齿 Schiff碱镍()配合物(2),X射线衍射结果表明,配合物 2属单斜晶系,P21/C空间群.a=1.1476(2)nm,b=1.1782(2)nm,c=1.4810(3)nm;β=111.73(2)°,V=1.8602(7)nm3,Z=4,Rf=0.0535.电化学(循环伏安)测定结果表明,该配合物在测定条件下(阳极峰电位为1.1)发生了不可逆的氧化-还原反应.

Relevância:

100.00% 100.00%

Publicador:

Resumo:

The crystal of complex [Li(THF)(4)][Fe(S2C2B10H10)(2)(THF)] 3 belongs to monoclinic, space group P2(1) with a = 11.964(2), b = 16.527(3), c = 12.554(3) Angstrom,beta = 108.70(3)degrees, V= 2351.3(8) Angstrom(3), Z = 2, M-r = 835.95, D-c = 1.181 g/cm(3), mu (MoKalpha) = 5.30 cm(-1), f(000) = '874, R = 0.0622 and Rw 0.1538 for 1641 observed reflections with I > 2sigma(I). The ionic complex,of 3 contains the square pyramidal anion of [Fe(S2C2B10H10)(2)(THF)](-) and the tetrahedral cation of [Li(THF)(4)](+). The iron is 5-coordinated and located in the square pyramidal configuration. The iron atom and the four sulfur atoms are almost coplanar. The Lithium atom is coordinated with four oxygen atoms of four THF molecules and located in a tetrahedral configuration.

Relevância:

100.00% 100.00%

Publicador:

Resumo:

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.

Relevância:

100.00% 100.00%

Publicador:

Resumo:

研究了聚苯胺 ( PAn)膜电极在 2 ,5-二巯基 -1 ,3 ,4 -噻二唑 ( DMc T)溶液中电化学处理或浸泡后的循环伏安 ( CV)曲线的变化规律 .实验结果表明 ,PAn膜电极在 DMc T溶液中进行电化学处理或浸泡过程可使DMc T进入 PAn膜内部与 PAn形成复合物 .PAn对 DMc T的电化学催化作用可能和二者之间形成的电子给体 -受体复合物有关 .该复合物的电化学氧化还原特性不同于 PAn和 DMc T,其氧化还原反应速率和可逆性均优于 DMc T

Relevância:

100.00% 100.00%

Publicador:

Resumo:

采用激光解吸电离飞行时间质谱 (LDI TOF MS)快速测定了 1H 2 ,3 二氢 1 吡咯里嗪酮衍生物相对分子质量 ,初步总结了该类化合物的质谱规律 .实验中不需加入基质 ,实测值与理论计算值相吻合.

Relevância:

100.00% 100.00%

Publicador:

Resumo:

利用溶胶 凝胶法合成了 (Ce0 .8RE0 .2 ) 1-xMxO2 -δ(RE :稀土 ,M :碱土 )系列固体电解质 ,XRD表明 80 0℃即形成萤石结构 ,较高温固相反应合成温度低约 70 0℃ .测定了样品的电导率和阻抗谱 .XPS测试表明 ,掺杂碱土氧化物后吸附氧浓度明显增大 ,氧空位增多 ,电导率和氧离子迁移数增大 ,改善了CeO2 基固体电解质的性能 .讨论了碱土及稀土离子对电性质的影响 .(Ce0 .8Sm0 .2 ) 1-0 .0 5 Ca0 .0 5 O2 -δ80 0℃时电导率0 1 2 6S·cm-1,氧离子迁移数 0 .99.

Relevância:

100.00% 100.00%

Publicador:

Resumo:

乙基苯基二氯化锡与2-羟基萘醛缩对甲氧基苯胺Schiff碱1∶1配合物的合成和晶体结构刘宝殿,包明,孙振刚,贺庆林,邢彦,贾恒庆,林永华(东北师范大学化学系,长春,130024)(中国科学院长春应用化学研究所,长春)关键词乙基苯基二氯化锡,Schif...

Relevância:

100.00% 100.00%

Publicador:

Resumo:

应用EI质谱和联动扫描技术研究了13个有机磷杂环化合物,讨论了主要离子的形成过程,分子离子在EI条件下的各种重排反应和取代基对不同解离反应产物离子相对强度的影响。

Relevância:

100.00% 100.00%

Publicador:

Resumo:

In the title compound, C21H16N4OS, the dihedral angles between the planes of the benzotriazole and N-phenyl rings and the plane of the atoms that link these two rings are 79.56 (6) and 59.02 (5) degrees, respectively, while that between the two benzene rings is 64.12 (6) degrees. There are some inter- and intramolecular interactions in the crystal structure.

Relevância:

100.00% 100.00%

Publicador:

Resumo:

In order to find leading compounds with an excellent fungicidal activity, the tide compound 2-(1,3-dithiolan-2-yl-idene) -1-phenyl-2-(1,2,4-triazol-1-yl) ethanone was synthesized according to the biological isosterism and its structure was confirmed by means of IR, MS, H-1 NMR and elemental analysis. The single crystal structure of the tide compound was determined by X-ray diffraction. The preliminary biological test shows that the synthesized compound exhibits some biological activities.