NaBH_3CN－ZnCl_2体系对含氧二茂铁衍生物的选择性还原

ＮａＢＨ＿３ＣＮ－ＺｎＣｌ＿２体系对含氧二茂铁衍生物的选择性还原林欣欣（中国科学院广州化学研究所广州５１０６５０）ＷＥＬｉｎｄｓｅｌｌ（ＤｅｐａｒｔｍｅｎｔｏｆＣｈｅｍｉｓｔｒｙ，Ｈｅｒｉｏｔ－ＷａｔｔＵｎｉｖｅｒｓｉｔｙ，ＵｎｉｔｅｄＫｉｎｇｄｏｍ...     

Synthesis, Characterization and Crystal Structure of a New Cobalt Phosphomolybdate that Contains [(Mo16O32)Co16(H2O)18(PO4)6(HPO4)18] Wheels

A new compound, [Co(H₂O)₆][{Co₂(H₂O)₆}{Co(H₂PO₄)₂}{(PO₄)₆(HPO₄)₁₈(Mo₁₆O₃₂)Co₁₆(H₂O)₁₈}] · 23H₂O (1), has been prepared under mild hydrothermal conditions and structurally characterized by elemental analyses, i.r. spectrum, XPS spectrum and single-crystal X-ray diffraction. Compound (1) consists of [(Mo₁₆O₃₂)Co₁₆- (H₂O)₁₈(PO₄)₆(HPO₄)₁₈] wheel-shape clusters as the structural motif, which are covalently linked by [Co₂(H₂O)₆] and [Co(H₂PO₄)₂] fragments to form a two-dimensional layer framework. It is the first time that such wheels have been linked by both mononuclear and dimeric Co^II octahedra. Electronic supplementary material Electronic supplementary material is available for this article at and accessible for authorised users.     

Separation of chiral furan derivatives by liquid chromatography using cyclodextrin-based chiral stationary phases

The enantiomeric separation of a set of 30 new chiral furan derivatives has been achieved on native and derivatized beta-cyclodextrin stationary phases using high performance liquid chromatography (HPLC). The hydroxypropyl-beta-cyclodextrin (Cyclobond RSP), the 2,3-dimethyl-beta-cyclodextrin (Cyclobond DM), and the acetyl-beta-cyclodextrin (Cyclobond AC) stationary phases are the most effective chiral stationary phases (CSPs) for the separation of these racemates in the reverse phase mode. No enantioseparations have been observed on the native beta-cyclodextrin chiral stationary phase (Cyclobond I 2000) and only a few separations have been attained on the S-naphthylethyl carbamate beta-cyclodextrin (Cyclobond SN) and 3,5-dimethylphenyl carbamate beta-cyclodextrin (Cyclobond DMP) chiral stationary phases in the reverse phase mode. The polar organic and the normal phase mode on these CSPs are not effective for separation of these compounds. The characteristics of the analytes, including steric bulk, hydrogen bonding ability, and geometry, play an important role in the chiral recognition process. The pH affects the enantioseparation of compounds with ionizable groups and the addition of 0.5% methyl tert-butyl ether to the mobile phase significantly enhances the separation efficiency for some highly retained compounds.     

负载Fe3（CO）12催化剂的制备及合成氨的催化活性

以Ｆｅ_３（ＣＯ）_（１２）为母体，以活性氧化铝或活性炭为载体制备了负载型氨合成催化剂．在固定床管式流动反应系统中测定了催化活性，并与以Ｒｕ_３（ＣＯ）_（１２）和ＲｕＣｌ_３·ｘＨ_２Ｏ为母体的负载催化剂以及低温高活性氨合成工业催化剂的活性进行了对比。结果表明：以活性炭为载体的Ｆｅ_３（ＣＯ）_（１２）催化剂在１５ＭＰａ、４００℃以上表现出很高活性，且每克纯活性组分的催化活性在某些温度下比当前活性较高的工业熔铁催化剂的活性要高得多，但低温常压下几乎无活性。负载钉催化剂在低温常压下即显活性，且以ＲｕＣｌ_３·ｘＨ_２Ｏ为母体，比以Ｒｕ_３（ＣＯ）_（１２）为母体的负载钌催化剂活性高。     

Use of chiral ionic liquids as solvents for the enantioselective photoisomerization of dibenzobicyclo[2.2.2]octatrienes

[Reaction: see text] Six chiral ionic liquids were prepared and evaluated as "chiral induction solvents" in which two different dibenzobicyclo[2.2.2]octatrienes were photoisomerized to chiral products. Enantiomeric excesses from 3 to 12% were obtained from the photochemical di-pi-methane rearrangement. Results indicate that the chiral induction derives from an ion pairing interaction of the deprotonated diacids with the ionic liquid cation. This is the first report on chiral induction via a chiral IL for an irreversible, unimolecular photochemical isomerization.     

Hydrothermal synthesis and characterization of two organically templated cadmium borophosphates with novel structures

Two organically templated cadmium borophosphates, (C(4)H(16)N(3))[CdClB(2)P(3)O(12)(OH)] (1) and (C(2)H(10)N(2))[CdB(2)P(3)O(12)(OH)] (2), were synthesized hydrothermally in the presence of structure-directing amines. Compound 1 has a complex layered structure (orthorhombic, Pbca (No. 61); a = 9.470(2), b = 12.307(3), c = 27.311(6) A; V = 3183 (1) A(3); Z = 8) with a 9MR channel system, while compound 2 (orthorhombic, Pbca (No. 61); a = 9.286(3), b = 12.459(3), c = 21.626(6) A; V = 2502(1) A(3); Z = 8) presents a 3-dimensional open framework structure of different types of intersecting channels. It is worth noting that both the Cl(-) anions and the organic templates play important and interesting roles in the formation of the structures.     

Highly Tough,Stretchable, Self-Adhesive and Strain-Sensitive DNA-Inspired Hydrogels for Monitoring Human Motion

Hydrogels used as strain sensors often rely on splicing tapes to attach them to surfaces, which causes much inconvenience. Therefore, to develop strain sensor hydrogels that possess both good mechanical properties and self-adhesion is still a great challenge. Inspired by the multiple hydrogen bonding interactions of nucleobases in DNA, we designed and synthesized a series of hydrogels PAAm-GO-Aba/Tba/Aba+Tba comprising polyacrylamide (PAAm), graphene oxide (GO), acrylated adenine and thymine (Aba and Tba). The introduction of nucleobases helps hydrogels to adhere to various substrates through multiple hydrogen-bonding interactions. It has also been found that the adhesive strength of hydrogels with nucleobases for hogskin increased to 2.5 times that of those without nucleobases. Meanwhile, these hydrogels exhibited good dynamic mechanical and self-recovery properties. They can be directly attached to human skin as strain sensors to monitor the motions of finger, wrist, and elbow. Electrical tests indicate that they give precise real-time monitoring data and exhibit good strain sensitivity and electrical stability. This work provides a promising basis from which to explore the fabrication of tough, self-adhesive, and strain-sensitive hydrogels as strain sensors for applications in wearable devices and healthcare monitoring.     

基于齿轮传动与红外遥感技术测量流速实验的设计与实现

流体流速是流体力学研究中最重要的参数之一,是判断流动稳定性与力学计算的基础,流速测量是实验研究中最必要的环节.本文主要对齿轮的各项物理特性及红外遥感技术进行深入的研究,设计了一组可以同时测出水流的平均速度与当前时刻水流瞬时速度的实验装置,以解决目前实验室测水流速课程中测量数据单一,实验仪器繁多等问题.设计的实验内容包括齿轮传动比的测量、基于单片机和齿轮组的路程时间测量,以及红外测速仪的瞬时速度读取,实验环节环环相扣,可以更好地锻炼学生的独立研究能力及培养学生的思维缜密性.通过上述实验,可以较为准确地测量出流体的平均流速以及在当前时刻的瞬时流速,并通过灵敏度的计算判断出各个参数对流速的影响比例.     

Electrochemistry of complex molecular and biomolecular scale entities

Structural mapping of intermediate size and large molecules and biomolecules at ultra-high resolution using single-crystal electrodes and in situ scanning tunnelling microscopy continues to disclose surprising findings. In situ scanning tunnelling spectroscopy has also recently disclosed new electrochemical conductivity features at the level of the single molecule. We overview briefly elements of this development over the last few years, with focus on three recent discoveries: (1) a new packing mode of a core monolayer target thiol, the amino acid cysteine (Cys) on Au(100)-electrodes, quite different from Cys packing on Au(111)- and Au(110)-electrodes; (2) transition of a core ferrocene in situ scanning tunnelling spectroscopy probe from stochastic single-molecule to macroscopic behaviour, a concept at the heart of nanoscience; and (3) unexpected behaviour of the large molybdenum enzyme sulfite oxidase, when going from macroscopic to single-molecule electrochemistry. We compare these studies with other recent discoveries of single-molecule protein conductivity and molecular scale inorganic nanostructures.     

Modeling dynamics of?disaster spreading in community networks

In this paper, we investigate the dynamics of disaster spreading in community networks. Unlike the case in other kinds of complex networks, the transitions between the self-healing and spreading dynamics for community networks are in ladder-type in dependent of the recovery time and time delay. Statistical analysis on the average erupting time of disaster in communities shows that large-scale disaster firstly erupts in the community with maximal average degree, which is unrelated with the location where the initial disturbance seed is. Moreover, the average erupting time of disaster reduces along with the decrease of the average degrees of communities. Therefore, the community structure is helpful on the control of the disaster spreading.