Reciprocal-space formulation and prediction of misfit accommodation in rigid and strained epitaxial systems
摘要:
几何特性在任何异质外延系统的描述中都是一个关键方面,其中方向、对称性和晶格参数各不相同。本文从Frank-van der Merwe理论的推广和Reiss与van der Merwe引入的刚性模型出发,推导出了一个基于能量的、本质上是几何性质的外延准则,用于平面界面的匹配。该准则最自然地以倒空间形式表述,即外延生长层和衬底的倒易晶格矢量匹配,并通过类似于Ewald构造的构建方法进行可视化。本文引入结构因子,考虑刚性平移以及衬底和外延生长层表面单胞的非原始性质。文章重点讨论了外延准则的推导及其后果,并将其作为描述外延结构、假同晶以及位错阵列或失配角尺阵列参数的基础,从晶体学的角度出发。该描述的优点在于其普遍性,因为它适用于任何晶体对称性或失配的组合,并可用于预测或解释界面结构。
Direct Synthesis of Substituted Pyrimidines and Quinazolines
作者:Mohammad Movassaghi、Matthew Hill
DOI:10.1055/s-2007-990932
日期:2008.3
A variety of N-vinyl and N-aryl amides were converted in one step into the corresponding pyrimidine and quinazoline derivatives, respectively. Amide activation with trifluoromethanesulfonic anhydride in the presence of 2-chloropyridine followed by nitrile addition to the activated amide derivative and annulation provides the desired azaheterocycles.
Preparation of Phenyl Cyanate and Its Utilization for the Synthesis of α,β-Unsaturated Nitriles
作者:Rex E. Murray、George Zweifel
DOI:10.1055/s-1980-28955
日期:——
One-pot synthesis of conjugated alkynenitriles from aldehydes
作者:Joong-Gon Kim、Eun Hwa Lee、Doo Ok Jang
DOI:10.1016/j.tetlet.2007.01.157
日期:2007.3
A method of preparing conjugated alkynenitriles was developed from various aldehydes with CCl3CN and PPh3 in the presence of (BuLi)-Bu-t. The reaction proceeded via alpha-chlorovinyl nitrile as an intermediate without any side reactions such as chlorination of starting aldehydes. (c) 2007 Elsevier Ltd. All rights reserved.