A Novel Inorganic Clathrate Generated through Arene‐Arene Interactions

The direct mixing of CoCl₂, sodium 2,6‐pyridinedicarboxylate (Na₂(2,6‐pda)), KSCN, and 1,2‐bis(4‐pyridyl)ethane (bpye) in water at the ambient temperature afforded purple crystals readily. The crystal structure, as determined by X‐ray diffraction crystallography, consists of discrete inorganic [Co₂(η³‐2,6‐pda)₂(μ‐SCN)₂(H₂O)₂] and organic bpye molecules. Adjacent dicobalt molecules are connected via intermolecular hydrogen bonds, to form one‐dimensional hydrophobic channels in the solid state, which serve as a host framework to incarcerate bpye guests inside. Every organic molecule attaches to four adjacent inorganic species via arene‐arene interactions. The facile approach in assembling the dicobalt and bpye molecules together into an inorganic clathrate is demonstrated.     

Density functional computations of the cyclopropanation of ethene catalyzed by iron (II) carbene complexes Cp(CO)(L)FeCHR,L = CO,PMe3, R = Me,OMe, ph,CO2Me

Density functional theory has been used to study the Fe‐catalyzed cyclopropanation of Fe‐carbene complexes with ethene. All the intermediates and transition states were optimized completely at the B3LYP/6‐31+G(d,p) level. Calculation results confirm that the cyclopropanation of Fe‐carbene complexes with ethene involves the two reaction paths I and II . In the reaction path I , the double bond of ethene attacks directly on the carbene carbon of Fe‐carbene complexes to generate the cyclopropane. In the reaction path II , ethene substitution for PMe₃ or CO in the Fe‐carbene complexes leads to the complexes M2 ; and the attack of one carbon of ethene on the carbene carbon results in the complexes M3 with a Fe? C? C? C four‐membered ring, and then generates the cyclopropane via the elimination reaction. For Fe‐carbene complexes A , C , D , E , and H , the main reaction mode is the reaction path I ; for Fe‐carbene complexes B , F , and G , the main reaction mode is the reaction path II . © 2007 Wiley Periodicals, Inc. Int J Quantum Chem, 2008     

Synthesis and cytotoxicity of nitrogen mustard/tripolypyrrole conjugate

A series of nitrogen mustard derivatives were synthesized by chloroform reaction and coupling reaction using DCC/ HOBT as promoting additives. The structure of compound was confirmed by ¹H NMR, ³¹P NMR, MS and IR. The data show that the nitrogen mustard with tripolypyrrole as the linker inhibits all the four tested cells and has the highest activity.     

微量热法研究头孢菌素对大肠杆菌微生物活性的影响

用微量热法测定了两种头孢菌素头孢哌酮钠(CFZ)和头孢哌酮钠舒巴坦钠(CFZ-SBT)在37 ℃时对大肠杆菌DH5α代谢作用的影响. 根据产热曲线分别获得了大肠杆菌DH5α在不同浓度的头孢哌酮钠和头孢哌酮钠舒巴坦钠作用下的生长速率常数(k)、抑制率(I)、最大产热功率(Pm)以及最大产热功率所对应的时间tm等热动力学参数. 研究结果表明, 头孢哌酮钠和头孢哌酮钠舒巴坦钠对大肠杆菌的致死量分别为0.1和0.25 μg/mL. 通过研究k, I, Pm, tm和浓度(c)间的关系发现, 舒巴坦钠的加入没有增加头孢哌酮钠对大肠杆菌DH5α的抑制作用.     

SYNTHESIS AND AVERAGE SEQUENCE LENGTH DETERMINATION OF AROMATIC-ALIPHATIC COPOLYESTERS CONTAINING POLY(ALKYLENE OXALATE) UNITS

Two series of aromatic-aliphatic random copolyesters(PEBTOXS)with diverse diol ratios have been synthesized by direct melting polycondensation.Two kinds of diols(glycol(EG)and 1,4-butanediol(BD))are used in combination in order to adjust crystallization and tensile properties,and three kinds of diacids(dimethyl terephthalate(DMT),diethyl oxalate(DEOX),and sebacic acid(SA))are involved.~1H-NMR spectra quantify both composition and structure,and show that the final contents in copolyesters appropriate to t...     

Study on the Retention Behavior of Aromatic Carboxylic and Sulfonic acid on a New Anion Exchange Column

Ion chromatography (IC) has gradually developed into a preferred method for the determination of inorganic anions. And in recent years some low molecular aliphatic acid can be also separated in the ion exchange column with the development of stationary phase. But for the determination of aromatic ionic compounds there are some problems. The aromatic anions show enhanced retention due to interaction with the π electrons of the aromatic backbone. Although the addition of an organic modifier can alleviate the difficulty, it is not the ultimate solution. IonPac AS20 column was developed using a unique polymer bonding technology and its substrate coating is aliphatic backbone. The polymer is completely free of any π electron‐containing substituents in the AS20 column. In this paper, the retention behavior of aromatic carboxylic and sulfonic acid on two hydroxide‐selective columns, IonPac AS11‐HC, AS16, and the new column AS20 was also studied. The result showed that the retentions of ten compounds on three columns were different with each other because of their different column characteristics. Among them 4‐chlorobenzene sulfonic acid, 3,5‐dihydric benzoic acid and salicylic acid obviously exhibited the weakest retention on the IonPac AS20. It was showed that π‐π bond function between anion and stationary phases was weakened in AS20 column because its polymer was completely free of any π electron‐containing substituents. So in this paper the AS20 was selected as an analytical column to separate ten aromatic ionic compounds, fumaric acid with conjugate bond included. The retention behavior, separation of the ten compounds and effect of temperature on their retention in the anion‐exchange column AS20 (2 mm) were studied. The result showed that those compounds could be separated with each other when running in gradient program and the organic modifier was unnecessary during the separation. So it is showed that AS20 column can be used as a separating column because its polymer is completely free of any π electron‐containing substituents. Finally, the effect of temperature on the retention behavior in AS20 column was studied and it was showed that the retention of nine compounds exhibited endothermic behavior.     

用聚乙二醇简便合成3-取代-1, 2, 3, 4-四氢吡啶并[3, 2-d]嘧啶-2, 4-二酮

用聚乙二醇作为可溶性聚合物载体和相转移催化剂高效简单的合成了1, 2, 3, 4-四氢吡啶并[3, 2-d]嘧啶类化合物。该合成路线为聚乙二醇与2, 3-吡啶二酸酐反应生成聚乙二醇支载的单酯1,接着1被转化成相应的聚乙二醇支载的酰基叠氮2,2经Curtius重排,与胺加成并同时关环给出目标产物,其总产率为84%-88%。     

制备溶剂对NiCoB非晶态合金催化剂结构及糠醛加氢性能的影响

采用化学还原法在不同单一和复配溶剂体系中制备了一系列NiCoB非晶态合金催化剂,对其液相糠醛加氢性能进行了考察,并采用N_2吸附-脱附等温线、ICP、FE-SEM、HRTEM、XRD、XPS等手段进行了表征。结果表明,在相同反应条件下,制备溶剂的表面张力、黏度、极性大小和溶解度常数等对NiCoB非晶态合金催化剂的组成、形貌和结构及其糠醛加氢反应性能均产生重要影响。由甲醇/乙二醇复配溶剂(MEG,体积比1∶1)制备的NiCoB-MEG催化剂具有最理想的糠醛液相加氢制糠醇性能,糠醛转化率达到96.4%,糠醇选择性达到83.49%,这可归因于甲醇和乙二醇之间的协同作用促进了金属组分的分散和还原。     

Amperometric sensing of hydrazine using a magnetic glassy carbon electrode modified with a ternary composite prepared from Prussian blue,Fe<Subscript>3</Subscript>O<Subscript>4</Subscript> nanoparticles,and reduced graphene oxide

A magnetic glassy carbon electrode (mGCE) was modified with a ternary composite prepared from Prussian blue (PB), magnetite (Fe₃O₄) nanoparticles, and reduced graphene oxide (rGO) in order to obtain an amperometric sensor for hydrazine. The utilization of Fe₃O₄ facilitates the magnetic immobilization and separation of sensing material, while the use of rGO enhances sensitivity. The surface coverage and the stability of the PB on the modified electrode were considerably improved. The electro-oxidative response to hydrazine was investigated with this modified mGCE using cyclic voltammetry and amperometric. The sensor, typically operated at a voltage of 0.2 V (vs. SCE), displays superior response hydrazine, with a response time of 4 s, a sensitivity of 97.73 μA μM^?1 cm^?2 and a 13.7 nM detection limit.

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Graphical abstract A magnetic glassy carbon electrode was modified with a ternary composite prepared from Prussian blue, magnetite nanoparticles, and reduced graphene oxide to obtain a selective amperometric sensor for dissolved hydrazine.

     

Cu(II)-catalyzed acetoxylation of arenes by 1,2,3-triazole-directed C–H activation

A facile and efficient method for the regioselective acetoxylation of 1-benzyl 1,2,3-triazoles through C–H bond activation was developed. Cu(OAc)₂ and 1,2,3-triazole were applied as catalyst and elegant directing group, respectively, to convert aromatic C–H bonds directly into highly regioselective C–O bonds. The conversion can result in the synthesis of 1,2,3-triazoles bearing acetoxyl groups.