1. Department of Chemistry, Boston University, Boston, Massachusetts 02215, United States
2. Departamento
de Química, Centro de Investigación en Síntesis
Química, Universidad de La Rioja, Madre de Dios, 51, 26004 Logroño, Spain
3. Department of Organic Material Science, Sandia National Laboratories, Albuquerque, New Mexico 87185-0886, United States