1. Department of Chemistry, Yale University, P.O. Box 208107, New Haven, Connecticut 06520, USA
2. Department of Chemistry, Fairfield University, 1073 North Benson Road, Fairfield, Connecticut 06824, USA
3. Department of Chemistry, University of Pittsburgh, 219 Parkman Avenue, Pittsburgh, Pennsylvania 15260, USA
4. Department of Chemistry and Biochemistry, University of Mississippi, University, Mississippi 38677, USA