1. Department of Chemistry, Babes-Bolyai University, Kogalniceanu Street #1, RO-400084 Cluj-Napoca, Romania, Hétérochimie Fondamentale et Appliquée, UMR 5069, Université Paul Sabatier, Toulouse III, 118 Route de Narbonne, 31062 Toulouse Cedex 04, France, Department of Chemistry, University of Bath, Bath BA2 7AY, U.K., and Departamento de Química, Universidade Federal de São Carlos, Via Washington Luiz, Km 235, Caixa Postal 676, São Carlos, SP Brazil