Topographical Analysis of Molecular Electrostatic Potential and Electron Density for Electron Distribution and Chemical Bonding in Polyacetylene Oligomers

Electron-localization and -delocalization are important factors of pi-conjugated conducting polymers. In the present work we studied the electron distribution of oligomers of simplest conducting polymer, poly acetylene i.e., H-(CH=CH)(n)-H (where n = 10 and 15) as test cases, by using density functional theory (DFT) calculations at B3LYP/6-31G (d, p) level of theory. Topography of the molecular electrostatic potential and molecular electron density is employed to analyze molecular electron localization, pi-electron conjugation and bonding features of the oligomers. It is found that the pi-electron localization and bond strength of the oligomers enhance from central pi-bonds to the terminal ones, however, pi-electron conjugation strength distributed evenly over the oligomers.