1. Departamento
de Química, Universidade Federal de São Carlos, São
Carlos, São Paulo CP 676, 13565-905, Brazil
2. Instituto
de Física de São Carlos, Universidade de São Paulo, São
Carlos, São Paulo 13560-970, Brazil
3. Goodwin
Laboratory, Massey Cancer Center, Virginia Commonwealth University, 401 College Street, Richmond, Virginia 23298, United States
4. Department
of Chemistry, Virginia Commonwealth University, 1001 W. Main Street, Richmond, Virginia 23284-2006, United States