1. Laboratoire de Chimie Supramoléculaire, ISIS, Université de Strasbourg, 8 Allée Gaspard Monge, 67000 Strasbourg, France
2. CNRS, CRPP, UMR 5031, F-33600 Pessac, France
3. Univ. Bordeaux, CRPP, UMR 5031, F-33600 Pessac, France
4. Solid State and Structural Chemistry Unit, Indian Institute of Science, C.V. Raman Road, Bangalore 560012, India
5. Laboratoire de Chimie Quantique, UMR 7177 CNRS, Université de Strasbourg, 1 rue Blaise Pascal, 67008 Strasbourg, France
6. Department of Chemistry, University of Cambridge, Cambridge CB2 1EW, U.K.