1. Instituto de Química, Facultad de Ciencias, Universidad Austral de Chile, Casilla 567, Valdivia, Chile, Facultad de Ciencias Químicas, Universidad de Concepción, Casilla 160-C, Concepción, Chile, and Materials Characterization Central Laboratory and Department of Applied Chemistry, School of Science and Engineering, Waseda University, Tokyo 169-8555, Japan