Synthesis,crystal structure,electrochemical properties and large optical limiting effect of a novel 3-(E)-ferrocenyl-vinyl-<Emphasis Type="BoldItalic">N</Emphasis>-hexyl carbazole

The novel compound, 3-(E)-ferrocenyl-vinyl-N-hexylcarbazole (FVHC) was first synthesized and fully characterized by elemental analysis, IR, ¹H-NMR, single-crystal X-ray diffraction, ultraviolet (UV) absorption, cyclic voltammograms (CV) and optical limiting (OL) measurements. The result of single crystal X-ray diffraction for the compound reveals that the ferrocenyl and carbazole groups are approximately coplanar, and bridged by double-bond with E configuration, showing that there is a well-delocalized π-electron system in the molecule. The electrochemical investigation indicated that the electron in the FVHC may partially be delocalized over the π-conjugated system and CT process in functionalized carbazole systems. Besides, the compound exhibited strong UV absorption and large optical limiting effect, indicating promising potential applications as useful OL materials.     

Aromatic poly(sulfone sulfide amide imide)s as new types of soluble thermally stable polymers

A new diamine monomer containing flexible sulfone, sulfide, and amide units was prepared via three steps. Nucleophilic chloro displacement reaction of 4‐aminothiophenol with 4‐nitrobenzoyl chloride in the presence of propylene oxide afforded N‐(4‐mercapto‐phenyl)‐4‐nitrobenzamide and subsequent reduction of the nitro intermediate led to 4‐amino‐N‐(4‐mercapto‐phenyl)benzamide. Two moles of this amino thiophenol compound was reacted with bis‐(4‐chloro phenyl)sulfone to provide a novel diamine monomer. The diamine was reacted with aromatic dianhydrides to form polyimides via a two‐step polycondensation method, formation of poly(amic acid)s, followed by chemical imidization. The resulting polymers were characterized and their physical properties including thermal behavior, thermal stability, solubility and inherent viscosity were studied. Copyright © 2007 John Wiley & Sons, Ltd.     

Yb2O3对TiO2/(O''+β'')-Sialon复相陶瓷中TiO2相变的影响

以纳米锐钛矿型TiO2粉和（O＇＋β＇）-Sialon粉为原料制备出了TiO2／（O＇＋β＇）-Sialon复相陶瓷，研究了Yb2O3添加剂对材料中锐钛矿型TiO2相变的影响，对其影响机制进行了探讨。采用XRD对材料进行物相组成和晶格参数表征。结果表明，Yb2O3对锐钛矿相变开始温度无明显影响，但对相变有显著的促进作用，随添加量的增加，其作用逐渐减弱。添加的Yb2O3同时以两种形式存在：一部分进入TiO2晶格，一部分堆积在TiO2晶粒表面。Yb^n＋进入TiO2晶格置换Ti^4＋和Yb^3＋与TiO2发生氧化还原反应促进相变，而存在于TiO2表面的Yb^3＋与TiO2相互作用形成Ti-O-Yb键而抑制相变。Yb2O3对锐钛矿相变的影响是这两方面机制共同作用的结果。     

功能化离子液体中Ag纳米微粒的制备及摩擦学性能研究

合成了1-甲基-3-羟乙基咪唑四氟硼酸盐离子液体([C₂OHmim]BF₄)，用红外光谱表征了其结构。以所合成的离子液体作为还原剂、稳定剂与反应介质制备了Ag纳米微粒，用XRD和TEM对微粒的结构和形貌进行了表征。在四球摩擦磨损实验机上研究了[C₂OHmim]BF₄离子液体及掺入Ag纳米微粒后的离子液体的摩擦学性能。掺入银纳米微粒后，离子液体在高载荷下的润滑性有了大幅的改善。用SEM和XPS分别对磨痕表面的形貌和元素组成、化学状态进行了分析，结果表明：在低、高载荷分别起润滑作用的是有机膜和金属-有机复合膜。     

ICP-AES法同时测定TiNi形状记忆合金中杂质Co、Cu、Cr、Fe、Nb

研究建立了ICP—AES同时测定TiNi形状记忆合金中Co、Cu、Cr、Fe、Nb5元素的方法。进行了必要的条件试验，选择了分析线及其他仪器工作参数；考察了方法检出限、H2SO4酸度及基体钛、镍对测定的影响、工作曲线线性。进行了准确度和精密度试验，各元素的加标回收率为Co98．4％。99．6％、Cu98．0％～103％、Cr98.9％～99．6％、Fe94．6％～95．8％、Nb99．8％。102％。5种元素的相对标准偏差范围为4．2％-10％。     

The oxidation of water by cerium(IV) catalysed by nanoparticulate RuO2 on mesoporous silica

Mesoporous silicates are prepared by templating on the hexagonal (H1) mesophase of surfactant bipyridine complexes of ruthenium(II) using a true liquid-crystal templating approach. On calcination, the surfactant template is removed except for the central metal ion that is oxidised, forming nanoparticles of RuO2 that deposit within the pores. RuO2 is a known oxidation catalyst and, despite its anhydrous nature in these silicates, is found to be very active in catalyzing the oxidation of water by acidic CeIV.     

High-yield solvothermal formation of magnetic CoPt alloy nanowires

One-dimensional (1D) magnetic nanomaterials have attracted much attention recently because of their applications in magnetic recording and spintronics. Nevertheless, it remains a challenge to prepare free-standing magnetic nanowires in high yield. This Communication reports the successful high-yield synthesis of an interesting 1D ferromagnetic CoPt alloy by direct decomposition of platinum acetylacetonate and cobalt carbonyl compound in ethylenediamine solvent through a solvothermal reaction. The CoPt alloy nanowires obtained have a tunable diameter of 10-50 nm and a length along the longitudinal axis of up to several microns, depending on crystallization temperature and reaction time. A unique formation mechanism involving coarsening and ripening under solvothermal conditions was discovered. This research opens new opportunities in synthesizing nanomaterials through low-temperature solvothermal processes.     

Physicochemical and structural properties of bacteriostatic sulfonamides: Theoretical study

A theoretical study at the Hartree–Fock and density functional theory levels is performed on sulfonamide‐type bacteriostatic compounds with the aim to provide an insight into their structure–activity relationship. The basicity of the p‐amino group is analyzed by means of the proton affinities and the protonation energies, showing that molecules presenting bacteriostatic activity are less basic, i.e., they are characterized by larger protonation energies and smaller proton affinities. The acidity of the amide group is analyzed through the deprotonation energy. The results reveal that the more acidic molecules present a larger bacteriostatic activity. This result is also confirmed from a study of bond orders. A bond order analysis of the amide group suggests that the electron attracting group in these molecules is responsible for the increase in acidity. The charge of the SO₂ group is also shown to be affected by the presence of the electron attracting group and consequently related to the acidity of the molecules. A geometric analysis shows that structures in which the amino group is more coplanar with respect to the benzenic ring possess larger bacteriostatic activity. A conformational analysis of these molecules illustrates that active molecules have relatively larger torsion energy barriers. © 2003 Wiley Periodicals, Inc. Int J Quantum Chem 94: 165–172, 2003     

氰戊菊酯立体异构体在手性键合相上的分析

本文介绍了采用高效液相色谱法在(R)-N-3,5-二硝基苯甲酰苯甘氨酸手性键合相上氰戊菊酯的四个立体异构体的分离,以外消旋氰戊菊酯样品为参照,计算了光学活性氰戊菊酯样品的四个立体异构体的百分含量,确定了在手性键合相上氰戊菊酯四个立体异构体构型的流出顺序为SR→RS→SS→RR。     

Two Novel Alkaloids from Zanthoxylum nitidum

Two novel alkaloids, 4,5‐dihydroxy‐1‐methyl‐3‐oxo‐2‐(trichloromethyl)‐3H‐indolium chloride ( 1 ) and 4‐(2‐methoxyethyl)‐N,N‐dimethylbenzenamine ( 2 ), were isolated from the EtOH extract of the roots of Zanthoxylum nitidum. Their structures were identified on the basis of spectroscopic and mass‐spectrometric analyses.