L-卡尼丁分子压印聚合物作为手性分离色谱固定相的研究

以L－卡尼丁为模板分子，分别以α－甲基丙烯酸和丙烯酰胺为功能单体，乙二醇二甲基丙烯酸酯为 剂，采用分子压印技术合成了对L－卡尼丁具有高选择性的分子压印聚合物。将所得聚合物用作高效液相色谱固定相，研究了它们对外消旋卡尼丁盐酸盐的拆分能力，分析结果表明，α－甲基丙烯酸作为功能单体所得聚合物对外消旋卡尼丁盐酸盐具有良好的拆分作用，其分离因子α为1．89。     

单向拉伸聚偏氟乙烯的取向结构

本文用X射线衍射法测定了单向拉伸聚偏氟乙烯的(110)和(020)晶面的极图,拉伸温度为100℃和160℃,拉伸比从250％—420％。利用衍射强度分布数据I(φ、ψ)计算出晶面均方余弦(cos~2(?)),经坐标转换并借助Wilchin-sky方法,得到c轴相对拉伸方向的均方余弦(cos~2φ_(c,y))。当T=100℃时,拉伸伴随有晶型转化,表现为晶面衍射峰强度和位置的变化,在此基础上对α晶型和β晶型的取向分别进行了分析。     

咪唑类离子液体结构与熔点的构效关系及其基本规律

熔点是界定、研究离子液体及其使用过程的一个重要参考指标,因此研究离子液体分子结构与熔点之间的构效关系及其基本规律有特别重要的意义。本文以从近两百遍文献及Beilstein Gmelin网络数据库中收集的约900种咪唑类离子液体中的384种咪唑类离子液体的熔点数据为依据,考察了离子液体分子结构与熔点之间的构效关系及其基本规律,这对离子液体的设计合成及应用有指导作用。     

Study on the anodic reaction of Ni in an alkaline solution by transient pH detection based on scanning electrochemical microscopy (SECM)

The anodic reaction of Ni in an alkaline solution was studied by the tip–substrate voltammetry mode of scanning electrochemical microscopy (SECM) and cyclic voltammetry (CV). A platinum microdisc electrode was selected as the tip electrode, which functioned as a pH sensor with transient response capability. The pH value of the solution near the Ni electrode surface varied while the Ni substrate oxidation reaction occurred, and the pH variation could be detected by the tip faradic current. The cyclic voltammogram results showed that two types of hydroxides: i.e. α‐Ni(OH)₂ and β‐Ni(OH)₂ were formed during Ni oxidation in the lower potential region. In the proceedings of α‐Ni(OH)₂ → γ‐NiOOH and β‐Ni(OH)₂ → β‐NiOOH, the process of OH^? concentration decrease in the solution was ahead and behind of electron transfer in the solid phase, respectively. These results indicate that the OH^? adsorption process occurs as an elementary step in the former reaction and the H⁺ diffusion process from the inner to the outer layer of the solid phase occurs as a subsequent step in the latter reaction. The results also revealed that the oxide film on the Ni surface has a two‐layer structure. The real potential of the oxygen evolution reaction (OER) on the Ni surface with different cycles is also analyzed in the paper. Copyright © 2007 John Wiley & Sons, Ltd.     

介质对配合物稳定性的影响——Ⅳ. Cu(SCN)+-NaNO3-tert-Butyl Alcohol-H2O体系，25℃

本文用分光光度法确定了25℃下配阳离子Cu(SCN)⁺在NaNO₃-叔丁醇-水介质中的稳定常数。混合溶剂中叔丁醇组成为0，5，10，15，20和25 wt%，离子强度范围为0.2～3.0 mole·dm^-3，溶液的pH=1.5～1.6。基于Pitzer理论用最小二乘多项式逼近法，确定了混合溶剂中配合物热力学稳定常数。讨论了配位反应的一级介质效应。     

An efficient method for constructing nonorthogonal localized molecular orbitals

A new method for constructing nonorthogonal localized molecular orbitals (NOLMOs) is presented. The set of highly localized NOLMOs is obtained by minimization of the spread functional starting from an initial set of canonical orthogonal molecular orbitals. To enhance the stability and efficiency, the centroids of the NOLMOs are constrained to be those of the corresponding orthogonal localized molecular orbitals (OLMOs), which are obtained with the Boys criterion in advance. In particular, these centroid constraints make the optimization for each NOLMO independent of the others, which is an attractive feature for application to large systems. The minimization with the constraints incorporated through the multiplier-penalty function method is stable and efficient in convergence. While exhibiting the classical bonding pattern in chemistry and sharing a spatial distribution similar to that of the corresponding OLMOs, the obtained NOLMOs are more compact than the corresponding OLMOs with about 10%-28% reduction in the value of the spread functional and devoid of the troublesome "orthogonalization tails."     

菲林B近红外分光光度法测定维生素C

在pH 3的三氯乙酸酸性介质中,菲林B可以定量地将还原型维生素C氧化成脱氢型维生素C,利用脱氢型维生素C在920 nm处有最大吸光度,测定其含量,建立了一种测定维生素C的新方法,并研究了影响反应的各种因素。该方法对维生素C的检出限为0.17 mg/L;线性范围为0.5~10 mg/L,对水果中维生素C含量测定的RSD<2.31%;回收率为99.7%~101.1%,比2,4-二硝基苯肼分光光度法测定结果的相对偏差<±1.6%。     

两个具有PTP1B抑制活性的4-羟基丁内酯化合物的全合成研究

Two new naturally 4-hydroxylated butenolides were concisely synthesized in excellent enantiomeric purities. An aldol condensation and a Suzuki reaction served successfully as the key steps in the synthesis.     

Remarkably efficient oxidative coupling of N,N-dialkylarylamines in water mediated by cerium(IV) ammonium nitrate

A highly effective, economical, and environmentally friendly method using of CAN as oxidant and water as solvent for oxidative coupling of N,N-dialkylarylamines was reported.     

铝交联皂石的合成和表征及催化性能

用XRD、化学分析、IR、MASNMR、TPD等手段表征了合成皂石及其铝交联物的结构。结果表明:皂石的交联密度与四面体层电荷和交联条件(Al/土比)有关。在乙醇氨化反应中,交联皂石显示了较好的催化活性和选择性。皂石的交联密度与液相产物分布的关系表明层柱材料对此反应具有择形催化作用。醇氨化反应可能是在吸附态NH_3和气相醇分子间进行的。