1. Departamento de Química, Instituto Tecnológico e Nuclear, Estrada Nacional 10, P-2686-953 Sacavém Codex, Portugal, Department of Chemistry, Illinois State University, Normal, Illinois 61790, Department of Chemistry and Structure Determination Laboratory, University of Alberta, Edmonton, Alberta, Canada T6G 2G2, and Chemical Science and Technology (CST) Division, Los Alamos National Laboratory, Los Alamos, New Mexico 87545