1. Laboratoire de Chimie Univ. Lyon, ENS Lyon, CNRS, Université Lyon 1 46 Allée d'Italie 69364 Lyon France
2. Aix Marseille Univ CNRS UMR 7325, CINaM Campus de Luminy, case 913 13288 Marseille cedex 09 France
3. School of Chemistry and Biochemistry Center for Organic Photonics and Electronics Georgia Institute of Technology 901 Atlantic Drive NW Atlanta Georgia 30332-0400 United States