DFT Studies on Hydrogen Overfall Mechanism for Catalyzed Hydroisomerization of Pentane

The mechanism and related reaction paths in the hydroisomerization of n-pentane were studied by DFT calculations at the B3LYP/6-311++G** level. Two possible transition states were theoretically predicted and verified by the vibration frequency analysis as well as the calculations of intrinsic reaction coordinates (IRC). Furthermore, the related reaction barriers were evaluated by single point energy at the MP2/6-311++G** level with zero point vibration correction of DFT method. Thus, it is concluded that the isomerization might go through two pathways.     

Synthesis, Structure and Antibacterial Activities of 4-BBTS Schiff Base and Its Complexes

4-Bromobenzaldehyde thiosemicarbazone Schiff base (4-BBTS) and its Cu(II), Zn(II), Co(II) and Ni(II) complexes were synthesized and characterized by elemental analysis, UV, IR, MS, 1H NMR, and molar conductivity. Using disc diffusion method, the antibacterial activity tests were conducted. The results revealed that the ligand as well as all the complexes exhibits good antibacterial activities against E. Coli. and S. Aureus. Moreover, Cu(II) complex shows the best antibacterial activity, which provides beneficial reference for studying the relationship between the structures and performances.     

新型对称烷基咪唑离子液体介质中酶催化合成l-乙酸薄荷酯

设计合成三种新型对称烷基咪唑六氟磷酸盐离子液体——1,3-二正丁基咪唑六氟磷酸盐([DnBIM][PF6]), 1,3-二异丁基咪唑六氟磷酸盐([DiBIM][PF6])和1,3-二仲丁基咪唑六氟磷酸盐([DsBIM][PF6]). 以脂肪酶pseudomonas cepacia催化l-薄荷醇和乙酸酐的酯化过程为模型反应, 分别考察不同介质中酶的活性、反应性和稳定性, 结果表明作为反应介质三种新型离子液体均优于经典离子液体1-正丁基-3-甲基咪唑六氟磷酸盐和有机溶剂正己烷. 在三种新的离子液体中, [DiBIM][PF6]具有最好的亲生物性而被选择作为模型反应介质. 此外, 影响l-薄荷醇转化率的各种因素(包括反应温度、底物投料比、离子液体用量和含水量)及酶的重复利用性也被详细研究. 在最佳反应条件下, l-薄荷醇转化率达到97.4%, 酶促反应速度、平衡转化率和半衰期分别是正己烷中的12.7, 4.6和15.1倍. 脂肪酶重复使用10次后催化活性没有明显减少. 由于三种新型离子液体互为同分异构体, 以上事实还表明除憎水性和亲核性以外离子液体的空间构型也是影响酶行为的一个重要因素.     

应用腙作为配体的铜催化二芳醚合成反应

一种简单易得的腙,2-吡啶醛 1-苯基腙 （1）,能够作为有效配体,极大地促进碘化铜催化的芳基溴与酚的C–O偶联反应。该偶联反应条件温和（二氧六环为溶剂、磷酸钾为碱、90–100 0C 的反应温度）,适用于各种芳基溴（电中性、贫电子和富电子）和酚（电中性和富电子）的底物,能够相容一些碱敏感官能团如酯基、醛基和羰基等。     

四硫富瓦烯四硫纶桥联金属邻菲啰啉配合物的合成与性质

以2,3,6,7-四(2’-氰乙硫基)四硫富瓦烯为桥配体的前驱物, 合成了标题配合物μ-(ttftt)-[M(phen)]2 (M＝MnII, FeII, CoII, NiII, CuII, ZnII). 配合物的结构和性质经由元素分析、核磁共振波谱、红外光谱、紫外-可见光谱、荧光光谱、摩尔电导率和量子化学计算表征, 研究了电氧化还原和对Li/SOCl2电池的催化特性. 发现铁和钴配合物具有较高的催化活性且有利于电池的大电流和低温放电, 在25 ℃和电流密度25 mA/cm2条件下铁配合物使电池的电压和容量分别提高了133 mV和218 mAh.     

Synthesis and Crystal Structure of Ni(Ⅱ) Complex with N-Salicylaldehyde-N''''-phenoxyacetylhydrazine Ligand

1INTRODUCTIONHydrazoneshavebeenattractingmuchatten-tionfromchemistsinrecentyearsbecauseoftheirbiologicalactivities,chemicalandindustrialversa-tility,andstrongtendencytochelatetotransitionmetals[1,2],lanthanidemetals[3]andmaingroupmetals[4,5].Inthehydrazonecomplexes,thehydra-zoneligandcanactasaneutralormononegativebidentateligand,orevenasadianionictridentateliganddependingonthedonoratomsoftheligandsandthereactionconditions.Ontheotherhand,variouscompoundsderivedfromphenoxyaceticacidareveryus…     

Quantitative Correlation of Chromatographic Retention and Acute Toxicity for Alkyl（1- phenylsulfonyl） Cycloalkane Carboxylates and Their Structural Parameters by DFT

1 INTRODUCTION Quantitative structure-activity relationship (QSAR)is one of the necessary methods that could be emp- loyed to evaluate the hazards of organic chemicals. QSAR equation could be applied to predict the biological activity of unknown compounds, espe- cially for initial screening and evaluation of toxic compounds[1]. Moreover, the quantitative relation- ship between molecular structure and chromatogra- phic retention (capacity factor lgKW) could also bedeveloped to explain …     

Simultaneous micellar electrokinetic chromatographic determination of isomeric fatty acid hydroperoxides and corresponding hydroxy fatty acids

The high selectivity and efficiency of micellar electrokinetic chromatography with a borax-sodium dodecylsulfate (SDS) or meglumin-SDS buffer make possible the rapid separation of hydroperoxy and hydroxy fatty acids and the non-oxidised unsaturated fatty acids from which they are derived. Nearly all the isomers of the hydroperoxides and hydroxy fatty acids derived from oleic, linoleic, alpha- and gamma-linolenic and arachidonic acids can be determined both qualitatively and quantitatively within ca. 10 min. The system has as many as 1 x 10(6) theoretical plates, and the detection limits with UV diode array detection at 195 or 234 nm are in the micromolar range.     

Hydrothermal Synthesis and Structure of a Novel 1-D Mn(II) Compound with Carboxlyto and Imidazole Ligands

1 INTRODUCTION Mn complexes containing carboxylato ligands attract considerable interest due to the richness in structural chemistry[1～4] and potential applications in catalysis[5, 6], for example, some highly efficient Mn catalase mimics[7, 8]. Recently, we focus on the hy- drothermal synthesis of manganiferous coordination polymers using multiple carboxylato and nitrogen- containing ligands[9, 10]. As one of the interesting bridge ligands, terephthalato ligand (ta) can provide multipl…     

SYNTHESIS AND CHARACTERIZATION OF ORGANO-SOLUBLE FLUORINATED POLYIMIDES FROM 4,4''''-BIS(3-AMINO-5-TRIFLUOROMETHYLPHENOXY)-BIPHENYL AND VARIOUS AROMATIC DIANHYDRIDES

An aromatic diamine monomer,4,4'-bis(3-amino-5-trifluoromethyl phenoxy)-biphenyl (TFBPDA),wassynthesized via the nucleophilic displacement reaction of 3,5-dinitrobenzotrifluoride and 4,4'-biphenol.The monomer wasreacted with various aromatic dianhydrides via the high temperature polycondensation procedure to provide a series ofpolyimides.The polyimides,PI-1 to PI-4,show good solubility not only in aprotic solvents,such as N-methyl-2-pyrrolidinone and N,N-dimethylacetamide,but also in many common solvents,such as m-cresol,chloroform andcyclopentanone.PI-4,derived from 4,4'-(hexafluoroisopropylidene)diphthalic anhydride and TFBPDA,was even soluble intoluene.Moreover,PI films exhibit good thermal stability,outstanding transparency in the visible light region and acceptablemechanical and electrical properties.The excellent combined properties of the polyimides make them as a good candidate forfabricating microelectronics.