局部影响分析中的一种新二阶方法

本文通过考察一种新影响图的保形法曲率,给出一种新二阶局部影响分析方法,并通过实例验证了该方法的有效性.     

New chiral α‐diimine nickel(II) complexes bearing ortho‐sec‐phenethyl groups for ethylene polymerization

A series of new α‐diimine nickel(II) catalysts bearing bulky chiral sec‐phenethyl groups have been synthesized and characterized. The molecular structure of representative chiral ligand, bis[N,N′‐(4‐methyl‐2,6‐di‐sec‐phenethylphenyl)imino]‐1,2‐dimethylethane rac‐1c and chiral complexes, {bis[N,N′‐(4‐methyl‐2‐sec‐phenethylphenyl)imino]‐2,3‐butadiene}dibromidonickel rac‐2a and bis{bis[N,N′‐(4‐methyl‐2‐sec‐phenethylphenyl)imino]‐2,3‐butadiene}dibromidonickel rac‐2b, were confirmed by X‐ray crystallographic analysis. Complex rac‐2c bearing two chiral sec‐phenethyl groups in the ortho‐aryl position and a methyl group in the para‐aryl position, activated by diethylaluminum chloride (DEAC), showed highly catalytic activity for the polymerization of ethylene [4.12 × 10⁶ g PE (mol Ni.h.bar)^?1], and produced highly branched polyethylenes under low ethylene pressure (branching degree: 104, 118 and 126 branches/1000 C at 20, 40 and 60°C, respectively). Chiral 20‐electron bis‐α‐diimine Ni(II) complex rac‐2b also exhibited high activity toward ethylene polymerization [1.71 × 10⁶ g PE (mol Ni · h · bar)^?1]. The type and amount of branches of the polyethylenes obtained were determined by ¹H and ¹³C NMR. Copyright © 2013 John Wiley & Sons, Ltd.     

Nickel(II)-α-diimine complexes containing naphthyl substituents for ethylene polymerization under low ethylene pressure

Two new α-diimine containing Ni(II) complexes, {bis[N,N′-(2,6-dimethyl-4-naphthylphenyl)imino]-1,2-dimethylethane}dibromonickel 3a and {bis[N,N′-(2-methyl-4-naphthylphenyl)imino]-1,2-dimethylethane}dibromonickel 3b were synthesized and characterized. The crystal structures of representative ligand 2a and its complex 3a were determined by X-ray crystallography. Complex 3a bearing 2,6-dimethyl and 4-naphthyl groups, activated by diethylaluminum chloride (DEAC), shows high catalytic activity for the polymerization of ethylene [4.43 × 10⁶ g PE/(mol Ni h bar)]. Interestingly, complexes 3a and 3b bearing the naphthyl substituent in the para-aryl position produced dendritic polyethylenes (branching degree, 3a: 112, 118, and 147; 3b: 113, 127, and 151 branches/1,000 C at 20, 40, and 60 °C, respectively). The dendritic polyethylene particle size obtained by 3a and 3b/DEAC can be controlled in the 1–20 nm range under low ethylene pressure (diameter, 3a: 18.31, 14.44, and 11.09; 3b: 12.29, 8.98 and 6.27 nm at 20, 40, and 60 °C, respectively) and could be expected to produce a nano-targeted drug carrier after modification with water-soluble oligo(ethylene glycol).     

Ag/AgBr/Co–Ni–NO3 Layered Double Hydroxide Nanocomposites with Highly Adsorptive and Photocatalytic Properties

A facile anion‐exchange precipitation method was used to synthesize bifunctional Ag/AgBr/Co–Ni–NO₃ layered double hydroxide (LDH) nanocomposites by adding AgNO₃ solution to a suspension of Co–Ni–Br LDH. The Ag/AgBr nanoparticles were highly dispersed on the sheets of Co–Ni–NO₃ LDH. The prepared nanocomposites were used to adsorb and photocatalytically degrade organic pollutants from water. Without light illumination, the nanocomposites quickly adsorbed methyl orange, and the adsorptive capacity, which can reach 230 mg g^?1, is much higher than those of Co–Ni–Br LDH, Ag/AgBr, and activated carbon. The photocatalytic activities of the nanocomposites for the removal of dyes and phenol are higher than those of Co–Ni–Br LDH and Ag/AgBr. The proposed method can be applied to prepare other LDH/silver salt composites. The high absorptive capacity and good photocatalytic activity of such nanostructures could have wide applications in wastewater treatment.     

Molecular Geometry Optimization, Two-Photon Absorption and Electrochemistry of New Diphenylethylene Derivatives Linking with Benzophenone Moiety Through Ether Covalent Bond

This paper presents the molecular geometry optimization, two-photon absorption and electrochemistry of new dyes containing benzophenone part, including 4-(p-benzoyl-benzyloxy)yl-4'-nitro-diphenylethylene (C1), 4-[N-methyl-N-(2-(p-benzoyl-benzyloxy)yl-ethyl]-4'-nitro-diphenylethylene (C2), 4-[N-ethyl-N-(2-(p-benzoyl-benzyloxy)yl-ethyl]-4'-nitro-diphenylethylene (C3), and 4-N, N-bis[(2-(p-benzoyl-benzyloxy)yl-ethyl]-4'-nitro-diphenyl ethylene (C4). The molecular structural parameters show that the coplanarity of diphenylethylene moiety is diminished in the excited state for C1, while it is enhanced for C2, C3 and C4. The electron density distribution of frontier orbital suggests that the derivatives exhibit (π, π) transition with internal charge transfer character, and the extent of charge transfer of C2, C3 and C4 is larger than that of C1. The derivatives display remarkable two-photon absorption (TPA) induced up-converted emission under 800 nm Ti: Sapphire femtosecond laser excitation. The maximal TPA emission wavelength of C2, C3 and C4 is red-shifted with respect to that of C1. TPA cross sections of C2, C3 and C4 are larger than those of C1. The cyclic voltammograms and the fluorescence lifetimes of the derivatives were determined and discussed.     

An Effective and Convenient Method for the Preparation of KAD‐1229

A new convenient method for the asymmetric synthesis of the potent hypoglycemic agent KAD‐1229 was developed. The key step of this method is diasteroselective alkylation of 1 to give crude 2 (d.e.>93%) in good yield with the easily available Oppolzer's camphorsultam as chiral auxiliary. The overall yield of the product was 57%.     

Magnetic metal–organic framework MIL‐100(Fe) microspheres for the magnetic solid‐phase extraction of trace polycyclic aromatic hydrocarbons from water samples

In this work, a magnetic metal–organic framework designated as MIL‐100(Fe) was prepared and applied as a magnetic solid‐phase extraction sorbent for the determination of trace polycyclic aromatic hydrocarbons in environmental water samples by coupling with high‐performance liquid chromatography and fluorescence detection. The magnetic microspheres exhibited large surface areas and high extraction ability, making them excellent candidates as sorbents for enrichment of trace polycyclic aromatic hydrocarbons. Under the optimized experimental conditions, good sensitivity levels were achieved with low detection limits ranging from 32 to 2110 pg/mL and good linearities with correlation coefficients higher than 0.9990 for the investigated 13 polycyclic aromatic hydrocarbons. The proposed method has been validated in the analysis of real water samples with mean recoveries in the range of 81.4–126.9% at four spiked levels and the relative standard deviations in the range of 1.3–17.0%. The magnetic MIL‐100(Fe) microspheres were stable enough for 150 extractions without a significant loss of extraction performance.     

吡唑并[4',3':5,6]吡喃并[2,3-d]嘧啶化合物的合成与生物活性

应用串联氮杂Wittig反应设计合成了一系列新的2-烷氨(芳氧)基-3,8-二苯基-5-芳基-6-甲基-5,8-二氢-4H-吡唑并[4',3':5,6]吡喃并[2,3-d]嘧啶-4(3H)-酮衍生物。通过氢核磁共振谱仪(1H NMR)、傅里叶变换红外光谱仪(FTIR)和元素分析等方法对所合成的化合物进行了结构表征,用X射线单晶衍射确证了化合物2-二正丙基氨基-3,8-二苯基-5-(4-甲基苯基)-6-甲基-5,8-二氢-4H-吡唑并[4',3':5,6]吡喃并[2,3-d]嘧啶-4(3H)-酮(Ⅲi)晶体结构。室内的杀菌和杀虫活性测试结果表明:目标化合物具有一定的杀菌活性,其中部分化合物对黄瓜灰霉菌(Botrytis cinereapers)在50 mg/L剂量下抑制率达到90%以上,显示了优异的杀菌活性;对水稻褐飞虱无明显的杀虫活性,但发现对粘虫具有较高的杀灭效果,大多数抑制率达到90%以上。     

新型N'-芳基亚甲基-N-(4-取代苯甲酰氧基噻唑-2-基)取代苯甲酰腙的合成与生物活性

利用生物活性亚结构拼接原理,将活性酰腙亚结构与活性噻唑环亚结构进行拼接,设计合成了14个新型N'-芳基亚甲基-N-(4-取代苯甲酰氧基噻唑-2-基)取代苯甲酰腙衍生物.所有目标化合物经1H NMR、IR、质谱及元素分析等手段进行了表征,部分化合物还经过13C NMR进行了确证.抗肿瘤测试结果表明,该系列化合物表现出明显的抗肿瘤活性,其对人口腔上皮癌细胞株(KB)的抑制活性优于对鼻咽癌细胞株(CNE2)的抑制活性;采用离体平皿法对目标化合物进行杀菌活性测试,测试菌种为:小麦赤霉菌、水稻纹枯霉菌、黄瓜灰霉菌、番茄早疫菌、烟草赤星菌和黄瓜炭疽菌.结果表明,在1.0×10-4 g/m L浓度下,目标化合物对部分菌种表现中等抑菌活性.     

An α-Diimine-Nickel(II) catalyst bearing an electron-withdrawing substituent for olefin polymerization

A Br-substituted α-diimine ligand, bis[N,N′-(4-bromo-2,6-dimethylphenyl)imino]-2,3-butadiene L1, and its corresponding Ni(II) complex, {bis[N,N′-(4-bromo-2,6-dimethylphenyl)imino]-2,3-butadiene} dibromonicke [NiBr ₂ (L1)], have been synthesized and characterized. The crystal structure of the free ligand (L1) was determined by X-ray crystallography. Two α-diimine-Ni(II) catalysts, {bis[N,N′-(2,4,6-dimethylphenyl)imino]-2,3-butanedione} dibromonickel [NiBr ₂ (L2)] and {bis[N,N′-(2,6-dimethylphenyl)imino]-2,3-butanedione} dibromonickel [NiBr ₂ (L3)], were also synthesized and characterized for comparison. The complex [NiBr ₂ (L1)], when activated by diethylaluminum chloride, produces the most active catalytic system for the polymerization of ethylene among the three complexes. NMR analysis shows that the degree of branching of polyethylene increases in the presence of electron-withdrawing groups under the same reaction conditions.