锌族和钛族卤化物振动光谱的理论计算

采用ab initio RHF,MP2和B3LYP方法以及LanL2DZ和SDD基组计算了四面体锌族卤素阴离子化合物(MX₄^2-,M=Zn(Ⅱ),Cd(Ⅱ),Hg(Ⅱ);X=F^-,Cl^-,Br^-,I^-)和钛族卤化物(MX₄,M=Ti(Ⅳ),Zr(Ⅳ),Hf(Ⅳ);X=F^-,Cl^-,Br^-,I^-)的几何构型和振动频率。计算结果表明,LanL2DZ基组是合适的基组,能得到合理的电荷分布,几何参数以及振动频率。在锌族卤化物的计算中发现,角弯曲振动频率与实测值相当一致,键伸缩振动频率略为偏低,这主要是由于计算的键长略为偏长所致。MP2方法计算的振动频率更接近于实测值。在钛族卤化物的计算中,三种计算方法都相当地再现了实测值,而以B3LYP方法更为满意。     

Synthesis and Crystal Structure of Diaquabis{2,4-dibromo-6-[(2-ethylaminoethylimino)methyl]-phenolato}nickel(Ⅱ) Dinitrate Diacetonitrile

The title mononuclear Schiff base nickel(Ⅱ) complex [Ni(C11H14Br2N2O)2(H2O)2]· 2NO3·2C2H3N was prepared and characterized by elemental analysis,IR spectrum,and single-crystal X-ray diffraction. The crystal belongs to the monoclinic system,space group P21/n with a=15.534(2),b=7.647(1),c=16.435(2),β=103.252(2)o,V=1900.3(4)3,Z=2,Dc=1.750 g/cm3,Mr=1000.99,λ(MoKα)=0.71073,μ=4.776 mm-1,F(000)=996,the final R=0.0368 and wR=0.0724. A total of 3988 unique reflections were collected,of which 2764 with I > 2σ(I) were observed. The complex consists of a mononuclear [Ni(C11H14Br2N2O)2(H2O)2]2+ cation,two nitrate anions and two acetonitrile molecules. The Ni atom,lying on the inversion centre,is six-coordinated by two Schiff bases and two water molecules to assume an octahedral coordination geometry. The molecules in the crystal are linked through intermolecular hydrogen bonds of N–H…O,N–H…Br,O–H…O,O–H…N and C–H…O to form layers.     

关环复分解反应(RCM)及其催化剂研究进展

综述了近年来关环复分解 (RCM )反应及其催化剂的研究进展 ,对RCM反应发展以来被广泛应用的催化剂 ,如Schrock催化剂和Grubbs催化剂等进行了归纳和总结 ,讨论了RCM反应在全合成中的应用     

合成甲醇的催化剂Rh-ZnO/MWNTs的研究

研究新型的由多壁碳纳米管(MWNTs)负载的， ZnO助催的铑基甲醇合成催化剂. 当铑含量达到4％(w)时，催化剂具有较高的比表面积(99.6 m2•g－1), 催化剂的反应活化能为68.8 kJ•mol－1.在563 K, 1 MPa下，催化剂的最高催化活性和甲醇选择性分别为411.4 mg/gcat.•h和96.7％. TEM、TPR和TPD等表征结果显示，碳纳米管能增加Rh在催化剂表面的分散度，提高催化剂的还原温度并能增加氢物种的吸附量，这些结果将有助于更好地了解催化剂中各组分间的协同作用和催化活性中心本质.     

超临界苯类溶剂对聚苯乙烯降解的影响

在高压间歇反应器中,温度340~370℃,以苯、甲苯、乙苯和对二甲苯为超临界溶剂研究了聚苯乙烯(PS)的降解特性.苯类物质是聚苯乙烯的优良溶剂,在超临界条件下其优异的传质、传热性能使聚苯乙烯快速降解.聚苯乙烯在不同超临界溶剂中降解转化率相近,而降解产物组成差别很大,分析了不同超临界溶剂对聚苯乙烯降解过程的影响.结果表明超临界甲苯对降解过程影响最小,苯乙烯收率最高.聚苯乙烯降解过程中,高分子链断裂和解聚同时进行,结合连续分布理论建立了聚苯乙烯降解的动力学模型,得到在超临界甲苯中聚苯乙烯链端解聚活化能为138.4 kJ.mol-1.     

Synthesis of 1,3,4‐Oxadiazoles and 1,3‐Thiazolidinones Containing 1,4,5,6‐Tetrahydro‐6‐pyridazinone

The reaction of 1,4,5,6‐tetrahydro‐6‐pyridazinone‐3‐carboxylic acid hydrazides ( 1 ) with aromatic aldehydes afforded 1,4,5,6‐tetrahydro‐6‐pyridazinone‐3‐carbonyl aromatic aldehyde hydrazones ( 2a‐2g ). Heterocyclic derivatives linked 1,3,4‐oxadiazole obtained by cyclocondensation of 2a‐2g with acetic anhydride in absolute ethanol, and 2a‐2g cyclized with mercaptoacetic acid in DMF in the presence of anhydrous ZnCl₂ afforded the 1,3‐thiazolidinone derivatives. The structures of the new compounds were established by elemental analyses, IR, ¹H NMR and MS spectral data.     

溶剂热法制备Ag/TiO2纳米材料及其光催化性能

以乙醇为溶剂, 钛酸四丁酯为前驱体, 用溶剂热法制备了Ag表面修饰的负载型纳米二氧化钛光催化剂. 利用X射线衍射(XRD)、N₂吸附-脱附(BET)、透射电子显微镜(TEM)、X射线光电子能谱(XPS)、紫外-可见(UV-Vis)光谱等技术对其进行了系统的表征, 以亚甲基蓝(MB)溶液的脱色降解为模型反应, 考察了不同Ag含量样品的光催化性能. 结果表明: 用溶剂热法制备的样品中TiO₂皆为锐钛矿相, 金属Ag颗粒沉积在TiO₂表面, 粒径为2 nm左右, 比表面积较溶胶凝胶法制备的样品大大增加, 最高可达151.44 m²·g^-1; UV-Vis光谱和光催化实验表明: Ag修饰使TiO₂对光的吸收能力大大增强, 吸收带边红移至可见光区, 亚甲基蓝在该复合材料上的光催化降解反应遵循一级反应动力学模型; 溶剂热法制备样品的光催化性能明显好于溶胶凝胶法制备的样品, 在紫外光和可见光下, Ag摩尔分数为5%的样品表现出最佳的光催化活性.     

Retention behaviour of carboxylic acid methyl esters in supercritical fluid chromatography

The study on retention behavior in supercritical fluid chromatography (SFC) is necessary to understand the mechanism of the various interactions in SFC. The retention of SFC in carboxylic acid methyl ester/polymethylsiloxane/CO2 system was studied systematically and the retention behavior of this kind of compounds under various typical operation conditions was described using the method of an alternative unified theory of chromatographic retention. The results illustrated that expression: Ink.= a + b/T + cp + dp/T + ep2/T can be used to describe quantitatively the retention behavior of carboxylic acid methyl ester/polymethylsiloxane/CO2 system in the ranges of reduced density from 0.549 to 1.411. It was also found that the entropy of solute in stationary phase is dependent on the density of supercritical fluid (SF) under typical operating conditions of SFC.     

用于燃料电池质子交换膜的含萘及氮杂环结构的新型磺化聚酰亚胺的合成及性能

将自制的4,4'-二氨基二苯醚-2,2'-二磺酸基(ODADS)、 含氮杂环芳香二胺1,2-二氢-2-(4-氨基苯基)-4-[4-(4-氨基苯氧基)-苯基]-二氮杂萘-1-酮(DHPZ-DA)和1,4,5,8-萘四甲酸二酐(NTDA)进行直接缩合聚合反应, 通过改变磺化二胺单体的含量来改变聚合物的磺化度, 成功地合成了一系列高分子量的不同磺化度的六元环聚酰亚胺(SPIs), 其特性粘度在0.55-1.47 dL/g. 采用FTIR和 1H NMR技术表征了聚合物的结构. 研究了经溶液浇铸成磺化聚合物膜的理化性质. 结果表明, 随着聚合物磺化度的增大, 膜的含水率和离子交换能力增大, 尺寸稳定性、 对水的稳定性以及抗氧化性降低.     

Z‐bpy,a New C2‐Symmetric Bipyridine Ligand and Its Application in Enantioselective Copper(I)‐Catalyzed Cyclopropanation of Olefins

A rigid C₂‐symmetric chiral bipyridine ligand Z‐bpy with a triptycene‐like backbone was designed and synthesized from simple chemicals in a scalable route. Using this new ligand, copper(I) catalyzed cyclopropanation of styrenes with commercial ethyl diazoacetate produced various corresponding cyclopropanes in high yields, diastereoselectivity and enantioselectivity up to 97% ee.