ELECTRONIC-STRUCTURE OF POLYSILANE OLIGOMERS

We present the results of valence effective Hamiltonian (VEH) nonempirical calculations on the electronic structure of linear oligosilanes, H(SiH2)(n)H containing up to 8 silicon atoms. The one-electron energy level distributions calculated for these systems are discussed in terms of their bonding nature and indicate that the HOMO and LUMO levels correspond to Si-Si sigma-bonding and antibonding molecular orbitals, respectively. The VEH results are found to be in excellent agreement with photoemission and UV absorption experimental data and illustrate the importance of backbone conformation. These studies show the reliability of the VEH method to deal with organopolysilanes.