1. Department of Chemistry, Stony Brook University, Stony Brook, New York 11794, United States
2. Facultad de Ciencias, Universidad Central de Venezuela, Caracas 1020-A, Venezuela
3. Zoneca-CENEX, R&D Laboratories, Alta Vista, 64770 Monterrey, México
4. Chemistry Division, Brookhaven National Laboratory, Upton, New York 11973, United States
5. Department of Chemistry & Biochemistry, Loyola University Chicago, Chicago, Illinois 60660, United States