1. Laboratory for Chemistry of Novel Materials, University of Mons, Place du Parc 20, BE-7000 Mons, Belgium, Institut des Sciences Moléculaires, UMR CNRS 5255, Université de Bordeaux, Cours de la Libération 351, FR-33405 Talence, France, and School of Chemistry and Biochemistry and Center for Organic Photonics and Electronics, Georgia Institute of Technology, 901 Atlantic Drive NW, Atlanta, Georgia 30332-0400, U.S.