熔体生长水杨酸苯脂晶体的形貌

在实验上用实时观察法和Kyropoulos技术生长水杨酸苯脂单晶,研究晶体形貌随过冷度的变化关系。在理论上采用Hartman-Perdok的PBC方法,分析水杨酸苯脂单晶形貌和晶体结构的关系。应用木原的核心势能模型,扩展了PBC理论。解析的晶体形貌与实时观察法得到的晶体形貌相当一致。 关键词：     

部分子结式性质的改进证明

为了更好的计算两个单变元多项式的最大公因式,20世纪初有Burside和Panton首先提出了结式的概念,在结式的基础上又提出了子结式的概念,这使得求最大公因式有了一个更系统的算法.计算机代数中关于子结式的经典定义过于繁琐,文献[1]中给出了子结式的一种简洁的定义.主要是借助文献[1]新定义的方法给出部分子结式的性质的证明及一些相应的例题,并对部分结论进行了一定的推广.     

Aminocarbonylation of aryl halides using a nickel phosphite catalytic system

The nickel and phosphite catalytic system with sodium methoxide enables a very efficient aminocarbonylation reaction to be performed between aryl iodides or bromides and N,N-dimethylformamide (DMF). Phosphite ligand 1, which is very stable to air and moisture and, furthermore, inexpensive, afforded the highest reaction yield.     

Copper-catalyzed decarboxylative coupling reactions for the synthesis of propargyl amines

When aryl alkynyl carboxylic acids were allowed to react with amines and aldehydes in CH₃CN at 80 °C in the presence of 10 mol % CuI, the desired propargyl amines were formed in good yields. This coupling reaction demonstrated to work across a broad range of reagents including functionalized aryl alkynyl carboxylic acids, aliphatic and aromatic aldehydes, and cyclic and acyclic amines.     

New group 4 half sandwich complexes containing triethanolamine ligand for polyethylene

(η⁵-C₅Me₅)M(TEA) (M = Ti, 1; Zr, 2; Hf, 3; TEA = triethanolateamine) was prepared by the reaction of (η⁵-C₅Me₅)MCl₃ with triethanolamine in the presence of NEt₃. The polyethylene catalytic efficiency in terms of activity decreases in the order 1/MAO > 2/MAO ? 3/MAO. In addition, the molecular weight (M_v) and melting temperature (T_m) of all the resulting polyethylene obtained by 2/MAO show the range of M_v = 91,200-356,200 and T_m = 137.0-141.9 °C, respectively; however, 1/MAO and 3/MAO gave polyethylenes with lower molecular weight (M_v = 6800-78,700) and lower melting temperature (T_m = 125.9-136.7 °C). Furthermore, 1/MAO showed significant decrease in the catalytic activity with increasing polymerization temperature though 2/MAO and 3/MAO have no dependence on the polymerization temperature.