1. Advanced Materials Research Institute, University of NewOrleans, New Orleans, LA 70148, USA
2. Department of Chemistry, University of New Orleans, New Orleans, LA 70148, USA
3. Department of Chemistry, North Carolina State University, Raleigh, NC 27695, USA
4. Department of Physics; University of Michigan, Ann Arbor, MI 48109, USA
5. New address: Materials Science and Engineering Department, University of Michigan, Ann Arbor, MI 48109, USA, Fax: +1‐734‐763‐4788