Abstract:

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.

Key words: Benzonitrile derivatives, Oligomer, Semiemperical calculationg, ZINDO