Iodine Polyphenylacetylene Charge-transfer Complex - An Abinitio Quantum-chemical Assessment

The ab initio MO-LCAO-HF method has been used to calculate the electronic structure of the iodine-polyphenylacetylene charge-transfer complex (PPA-I2). Two models have been considered for the PPA molecule: a simple one containing two phenyl groups and a more realistic one containing six phenyl groups. The calculations give automatically the charge separation between I5 and the polymer, and show that the total charge separation can be less than 1 e at short distances. The computed charges at the energy minimum have been successfully introduced into the curve fitting of the I-3d5/2 core level spectrum of PPA-I2 films, giving good agreement between experimental and theoretical results.