Abstract :
The molecular and electronic structure of a series of poly-amino-enolates is calculated ab initio within the density functional formalism using Car-Parinello molecular dynamics. Within this series, the bandgap is found to vary from 1 to 6.5 eV and the valence band is found to consist entirely of non-bonding orbitals. Both these features are essentially reproduced by a simple Hückel model. By variation of the Hückel parameters the important factors which determine the bandgap are identified. Hückel analysis furthermore demonstrates that the poly-amino-enolates are first examples of odd alternant conjugated polymers which allows the effects of the hetero atom substitution to be rationalised in terms of Dewarʹs colour rules for odd alternant systems.