1. Organic Semiconductor Centre, EaStCHEM School of Chemistry, University of St. Andrews, St. Andrews, Fife KY16 9ST, U.K.
2. Organic Semiconductor Centre, SUPA School of Physics and Astronomy, University of St. Andrews, St. Andrews, Fife KY16 9SS, U.K.
3. Laboratory for Chemistry of Novel Materials, University of Mons, 7000 Mons, Belgium
4. Unité de Chimie Physique Théorique et Structurale & Laboratoire de Physique du Solide, Namur Institute of Structured Matter, Université de Namur, Rue de Bruxelles, 61, 5000 Namur, Belgium