1. Département de Recherche Fondamentale sur la Matière Condensée, SCIB/Laboratoire de Chimie de Coordination (URA CNRS 1194), CEA-Grenoble, 38054 Grenoble, France, Department of Chemistry, University of Wrocław, 14 F. Joliot-Curie St., Wrocław 50 383, Poland, and Department of Chemistry and Biochemistry, University of Notre Dame, Notre Dame, Indiana 46556