Electronic Structures and Spectroscopic Properties of the Self-assembly Complexes for Dipyridone

Chao Yan and Shi Wu*
Department of Chemistry, Zhejiang University, Hangzhou 310 027, China
E-mail: wushi@zju.edu.cn; tel: 8657188206529; fax: 8657188206529

Abstract
The DFT and semiempirical methods were utilized to study the structures and spectra of the self-assembly complexes formed by dipyridone derivatives. The complexes with the negative binding energies could be formed via hydrogen bonding between two monomers. Due to the presence of the electron-donating substituents on the monomers, the binding affinities of the complexes were generally increased. Simultaneously, the LUMO-HOMO energy gaps of the complexes were widened, and the first absorptions in the electronic spectra were blue-shifted relative to that of the monomer. As the hydrogen bonds were formed, the IR stretching vibrations of the NH bonds in the complexes were weakened. The chemical shifts of the carbon atoms on the C=O bonds were changed downfield under the effect of the electron-donating groups.

Keywords: Dipyridone, hydrogen bonds, energy gap, B3LYP/3-21G.