1. Department of Photochemistry, UMR 7525 CNRS, University of Haute Alsace, ENSCMu, 3 rue Alfred Werner, 68093 Mulhouse Cedex, France, and Department of Organic and Bioorganic Chemistry, UMR CNRS 7015, University of Haute Alsace, ENSCMu, 3 rue Alfred Werner, 68093 Mulhouse Cedex, France