[ONSO]型Salen化合物的合成、单晶结构及金属离子识别

一些重金属离子即使在较低浓度时也会对环境、生物体产生毒性,所以研究痕量金属离子识别具有重大意义。荧光传感器由于具有选择性好、灵敏度高、成本低、实时响应等优点, 得到了广泛关注。以2,4-二叔丁基苯酚,3,5-二叔丁基水杨醛和邻氨基苯硫酚为原料合成了类Salen配体L1, 并用1H NMR,13C NMR,IR,元素分析及X射线单晶衍射等手段对其进行了表征。并通过自由挥发法得到了配体L1的单晶结构,实验表明L1是三斜晶、P-1空间群的一个空穴平面[ONSO]四配位环境。通过荧光光谱考察了类Salen配体与金属离子(Li+,Na+,K+,Cd2+,Cs+,Co2+,Cu2+,Hg2+,Mn2+,Ni2+,Zn2+,Ag+)的识别与配位性能。光谱滴定分析表明L1与Zn2+以1∶1的化学计量数配位。另外,L1与Zn2+结合后荧光显著增强,荧光检测限达到5.01×10-5 mol·L-1,而上述提到的其他常见金属离子不引起荧光光谱变化。结果表明L1是一个对检测Zn2+的选择性高,灵敏度强的荧光增强型探针。     

Exact solutions for four coupled complex nonlinear differential equations

In this paper, exact solutions are derived for four coupled complex nonlinear different equations by using simplified transformation method and algebraic equations.     

Phase stability and temperature effect in ScX (X=S,Se and Te) compounds

Based on first-principles calculations, the structural stability and temperature effect in ScX (X=S, Se and Te) compounds are studied with three typical structures of B1 (NaCl-type), hcp (NiAs-type) and β-hcp (inverse Li₂O₂-type). Their dynamic stability has been verified using phonon mode analysis and molecular dynamics simulations. From the total energy calculations, we find that the most stable ground state structures are B1 for ScS, and hcp for ScSe and ScTe, respectively. Moreover, structural stabilities at finite temperature are studied with the combination of phonon dependent dynamics analysis and first-principles calculations, which reveals a phase transition from hcp to B1 in ScSe around 230 K and a phase transition from hcp to β-hcp in ScTe around 460 K, in accordance with experimental findings. The energy barrier and pathway along the phase transformation from hcp to β-hcp ScTe are also calculated and analyzed by the solid-state nudged elastic band method.     

新型环氧水解酶手性拆分环氧氯丙烷的气相色谱法

建立了一种用于快速测定生物酶转化体系中手性环氧氯丙烷的气相色谱法。采用ZKAT-ChiralB毛细管柱,FID检测器检测,内标法计算含量。(R)-环氧氯丙烷和(S)-环氧氯丙烷在0.012～0.461g/mL呈良好的线性关系,RSD为1.3%、1.7%,回收率为97.6%、101.3%。     

Facile synthesis of core‐surface crosslinked nanoparticles by interblock RAFT polymerization

A new, efficient method for synthesizing stable nanoparticles with poly(ethylene oxide) (PEO) functionalities on the core surface, in which the micellization and crosslinking reactions occur in one pot, has been developed. First, amphiphilic PEO‐b‐PS copolymers were synthesized by reversible addition fragmentation chain transfer (RAFT) radical polymerization of styrene using (PEO)‐based trithiocarbonate as a macro‐RAFT agent. The low molecular weight PEO‐b‐PS copolymer was dissolved in isopropyl alcohol where the block copolymer self‐assembled as core‐shell micelles, and then the core‐shell interface crosslink was performed using divinylbenzene as a crosslinking agent and 2,2′‐azobisisobutyronitrile as an initiator. The design of the amphiphilic RAFT agent is critical for the successful preparation of core‐shell interface crosslinked micellar nanoparticles, because of RAFT functional groups interconnect PEO and polystyrene blocks. The PEO functionality of the nanoparticles surface was confirmed by ¹H NMR and FTIR. The size and morphology of the nanoparticles was confirmed by scanning electron microscopy, transmission electron microscopy, and dynamic laser light scattering analysis. © 2010 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem, 2010     

表面熔化

对近年来人们十分关注的表面熔化问题，从理论和实验上进行了综述性讨论。综述了一些金属晶体、冰及石墨吸附Ａｒ膜表面熔化的特征及其热力学理论解释。评述了半导体Ｇｅ（１１１）表面熔化的独特性质。     

Preparation of α,ω‐telechelic hexyl acrylate polymers with ?OH, ?COOH,and ?NH2 functional groups by RAFT

The design, synthesis, and use of two new, stable, functionalized chain transfer agents (CTA's) containing OH and amine end groups for the RAFT polymerization is reported: 2‐hydroxyethoxy‐carbonylphenylmethyl dithiobenzoate and 2‐(2‐(tert‐butoxycarbonyl)ethylamino)‐2‐oxo‐1‐phenylethyl benzodithioate, respectively. The RAFT polymerization of n‐hexyl acrylate (HA) using those CTA's, were compared to several other functionalized dithiobenzoate esters reported in the literature containing COOH and Ester groups. The performances of the dithiobenzoates were compared in terms of kinetics and molecular weight distribution control. Good control in polymerization of n‐hexyl acrylate with a linear increase of M_n with conversion mantaining polydispersity indices (PDI) below 1.1 was obtained by use of the new functionalized CTA's developed and also by use of some other CTA's tested, to produce well‐defined linear polymers with one specific chain‐end functionality: ? OH, ? COOH or Amine. Using a postpolymerization reaction with functionalized azocompounds in a 5 to 1 ratio, α,ω‐telechelic polymers, with ? OH or ? COOH as functional group at the second end were obtained. By using this synthetic strategy α,ω‐homotelechelic and heterotelechelic polymers were readily prepared. The chemical availability of functional end‐groups in the telechelics was demonstrated by reaction with methacrylic anhydride. © 2010 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 48: 3033–3051, 2010