双亲性含硫和含氮化合物有序单分子膜对碳钢的缓蚀作用

应用超分子组装技术将含硫儿含氮的双亲性金属缓蚀剂有序单分子膜按设计方式修饰在碳钢表面，探讨了在有主邓的单分子膜内缓蚀剂分子的排列对碳钢在硫酸中腐的抑制作用，深入讨论了缓蚀剂单分子膜对碳钢腐蚀过程的抑制机理，研究发现：在单分子膜中，水合氢离子传递的离子通道强烈地依赖于缓蚀剂分子的排列方式。     

Keggin结构的磷钨钒稀土四元杂多配合物对过氧化氢分解的催化作用

在磷钨钒稀土四元杂多配合物中，由于Ｖ原子的使用，使其对Ｈ２Ｏ２分解的催化活性显著增加。因配合物中心原子稀土元素不同。催化活性也随之变化，其活化能与三阶稀土离子的电离能有密切关系。动力学曲线为Ｓ型。实验证明，在反应过程中有反应活性中间体生成。     

四甲基二硅桥连双(四甲基环戊二烯基)四羰基二铁的反应性

标题化合物1与HgCl~2反应, 除生成希望的产物2外, 还分离到2的歧化产物3和4。1经Na-Hg还原, 生成Fe-Fe键断裂的双铁负离子5, 5分别与多种氯化物反应, 生成在铁原子上引入取代基的衍生物6, 7和8。以元素分析、IR及^1H NMR谱表征了化合物2-4及6-8的分子结构。     

介稳态氧化钨超微粉体的水热合成与光致变色性质研究

Under hydrothermal conditions, the superfine powders of cubic pyrochlore-type of tungsten oxide and hexagonal tungsten bronze were obtained by using Na₂WO₄·2H₂O as the starting material. The products were characterized by XRD, TG, IR, UV and EPMA, respectively. The effects of the pH value, the acid concentration, reaction temperature and time on the structure and particle size of products were investigated in detail. The conditions for the preparation of superfine powders of tungsten oxide were optimized. The pH 2.5～4.5 of the reaction system led to the formation of a pyrochlore phase and pH 0.5～2.0 gave the hexagonal tungsten bronze structure. The photochromism property of the hexagonal tungsten bronze was studied. The results show that pyrochlore and bronze phases are decomposed at 300 ℃ and 450 ℃, respectively. With the increasing of temperature, the structure of the two oxides changes. The pyrochlore-type powder changes completely into triclinic Na₂W₄O₁₃ around 500 ℃, while the bronze phase into a mixture of Na₂W₆O₁₉ and triclinic WO₃ at 550 ℃. The powder of the hexagonal tungsten bronze showed better photochromism property.     

一维链状4-羧基苯氧乙酸桥联钴配位聚合物[Co(p-CPOA)(2，2′-bipy)(H2O)]n的合成与晶体结构

A novel coordination polymer of [Co(p-CPOA)(2，2′-bipy)(H₂O)]_n (p-CPOA^2-=4-carboxylphenoxyacetate dianion, 2,2′-bipy=2,2′-bipyridine) was synthesized and characterized by elemental analysis, IR and X-ray single crystal diffraction. The title complex crystallizes in monoclinic space group C2/c, with a=1.424 4(3) nm, b=1.316 6(3) nm, c=1.947 7(4) nm, β=104.56(3)°. V=3.535 3(14) nm³, Z=8, R=0.028 5, wR=0.089 1. The cobalt(Ⅱ) ion displays a distorted octahedral coordination geometry, defined by three carboxyl oxygen atoms from different p-CPOA^2- groups, two nitrogen atoms from 2,2′-bipyridine ligand and one water molecule. The cobalt atoms are bridged by p-CPOA^2- groups, forming a one-dimensional chain structure along a axis. The adjacent Co…Co atoms distance is 0.996 8 nm. A layer supramolecular network is contrsucted by the hydrogen bonds and π-π stacking interactions. CCDC: 220039.     

一维链状2-氧-1(4H)-吡啶乙酸桥联钙配位聚合物[Ca(2-OPA)2(H2O)2]n的合成、晶体结构及热稳定性研究

A novel coordination polymer of [Ca(2-OPA)₂(H₂O)₂]_n (2-OPA-=2-oxo-1(4H)-pyridineacetate anion) was synthesized and characterized by elemental analysis, IR, TG and single crystal X-ray diffraction. The title complex crystallizes in orthorhombic with space group Pna2₁, a=0.799 96(16) nm, b=0.823 77(16) nm, c=2.415 3(5) nm, V=1.591 6(6) nm³, Z=4, R=0.030 3, wR=0.070 0. The Ca atom is eight-coordinated by six O atoms of four 2-OPA^- ligands and two water molecules, and displays a dodecahedron coordination geometry. Each 2-OPA^- ligand bridges two adjacent Ca atoms, forming a infinite chain along the a direction. The Ca…Ca distance is 0.4102 2(8)nm. A two-dimensional supramolecular framework is further constructed by the hydrogen bonds and the weak π-π interactions. The results of TG analysis show the chain structure of the title complex was stable under 297.5 ℃. CCDC: 251669.     

不对称氨羟化反应

介绍了Sharpless等人新近发现的不对称氨羟化反应,该反应可将烯烃直接转化成为手性β-氨基醇类化合物。对于有些烯烃,Sharpless不对称氨羟化反应具有高的区域选择性(20:1)和高的对映选择性(>98%e.e.)。     

“手”望相助，志虑忠“醇”

Through three stories about alcohol antiseptics, "hand" messengers, characters of the article find the best choice of alcohol, and method of application. This article introduces proper ways to use alcohol antiseptics in daily life from the following three aspects. The ethanol and propanol can be used, the best concentration for daily use is 70%, and the optimal use of alcohols is considered under different circumstances.     

紫外辐照对高密度聚乙烯分子结构的影响

紫外线;官能化;紫外辐照对高密度聚乙烯分子结构的影响