金属锌促进羰基化合物水相嚬呐偶合反应

报道了一种简便、有效的水相噤呐偶合反应。在含有少量季铵盐或季磷盐的氯化铵水溶液中．用金属锌促进羰基化合物进行水相噘呐偶合反应，其中加入的少量季铵盐或季磷盐有助于显著提高反应产率，噘呐醇产率由53％提高到87％。但噘呐偶合反应的产率受羰基周围环境的立体位阻影响较大，在此条件下，金属锌可有效地促进芳香族醛化合物进行水相噘呐偶合反应，得到产率较高的噘呐醇，但非对映异构体选择性差，而脂肪族醛化合物得到的噘呐醇产率较低，在同样条件下，酮类化合物不能顺利进行噘呐偶合反应。     

Adsorption and Vibration of O on the Pt Stepped Surfaces

1 INTRODUCTION Atom adsorption on transition metal surfaces has attracted special attention as a basis for understand- ing the fundamental processes of oxidative cataly- sis. An oxygen-covered platinum surface for example, plays a central role in several important reactions, such as oxidation of carbon monoxide[1]. Moreover, the behavior of oxygen in the proximity of surface defects like kinks and steps is a central issue in understanding the chemisorption processes on ca- talytic surfaces…     

催化动力学方法对智力碘口嚼片中总碘测定的研究

研究了采用动力学催化光度法微机测碘仪，结合ＨＸ－１型精密恒温消解仪，处理并测定智力碘口嚼片中总碘的方法。消解仪可同时处理６０个样品，消化时间６０ｍｉｎ，消化温度１３０℃。智力碘口嚼片测定均值为１９３．２×１０－６时的标准误差为２．５９，变异系数为１．３４％，回收率为９６．４％，检测限为０．２μｇ／Ｌ。     

TD-DFT Study on Pyrazoline Derivatives

1 INTRODUCTION Pyrazoline compounds have been widely used in industry due to their good photoconductivity and high fluorescence quantum productivity[1]. In recent years, pyrazoline derivatives with high vitrification temperature Tg have been found to act as hole trans- fer materials in the electroluminescence device, which has captured the intensive interest of che- mists[2]. But so far, the electron transfer mechanism of these compounds is still unclear[3~7]. Some resear- ches have attr…     

Synthesis and Crystal Structure of 1-D Chain Copper（Ⅱ） Complex： [Cu（L）Cl2]n （L=2,5-Di-2-pyridyl-1,3,4-oxodiazole）

INTRODUCTION The design and construction of the coordi- nation polymer with one-dimensional chain, two- dimensional layer or three-dimensional framework structure is of considerable interest and has been developing rapidly in recent years[1]. Relevant to…     

Synthesis and Crystal Structure of a Novel Two-dimensional Layered Polymer [Zn（μ-O2CCH=CHCO2）（C3H4N2）（H2O）]n

1 INTRODUCTION More than 200 known metalloenzymes of a wide variety of types have been shown to contain zinc centers at their active sites (such as hydrolases, ligases and anhydrases)[1～3]. The active zinc centers in biological systems are usually surro…     

N-茄呢基-N,N'-二(3,4-二甲氧基苄基)乙二胺的合成

茄呢基溴;;抗肿瘤药;N-茄呢基-N;N'-二(3;4-二甲氧基苄基)乙二胺的合成     

P350萃取色谱法分离微量钼（Ⅵ）的研究

低含量钼常用硫氰酸盐光度法测定,目前以水杨基萤光酮-溴化十六烷基三甲基胺光度法测定灵敏度最高,但一些高价金属离子有干扰,尤其钨(Ⅵ)和钛(Ⅳ)的干扰难以直接消除。因此,本实验系统地研究了甲基磷酸     

二氧化碳共聚物为基聚氨酯的生物降解性研究

以ＣＯ２为起始物合成生物降解型聚合物，既能利用丰富的ＣＯ２资源，减轻温室效应；又能减轻聚合物垃圾造成的污染。聚碳酸亚乙酯（ＰＥＣ）经动物体内实验和土埋实验，证明具有良好的生物降解性［１，２］。由ＰＥＣ合成的聚氨酯可获得有良好力学性能的材料，但是否具有...