取代基对苯腈类低聚物几何及电子特征的影响

用半经验量化计算研究了一系列苯腈类低聚合物的几何结构及其电子特征。苯腈类低聚合物几何结构的计算采用半经验量子化学计算和分子力学构象分析相结合的方法，而电子特征则的计算采用ＺＩＮＤＯ／Ｓ－ＣＩ方法。取代基包括甲氧基、甲基、羟基、氨基、氟和硝基。它们在苯环上可以采用邻位、间位和对位三个取代位置。计算结果表明，不同的基团在苯环上采用不同的取代位置时，低聚物的构象会存在一定的差别，而且电性会随着基团的得失

Substituent Effect on the Geometrical Structures and Electronic Properties of Benzonitrile Oligobenzonitriles

In this paper, semiempircal quantum chemistry calculations of geometrical structures, and energy level distributions of a series of substituted benzonitriles and their corresponding oligomers are presented. Geometrical calculations of benzonitril and substituted oligobenzonitriles are performed by using the AM1 method combined with molecular mechanical conformational analysis. The calculations of electronic properties are carried out by using ZINDO/S-CI method. The substituents studied possess a large range of δ-π electron-donor-acceptor capability, including methoxy, methyl, hydroxy, amino, flurine and nitro groups, located at para, meta and ortho-position in benzenoid ring. Theoretical calculations show that when different groups are substituted in different positions of the benzenoid ring, the oligomers show different geometrical characteristics and exhibit regular electronic variations.