1. School of Chemistry and Biochemistry and Center for Organic Photonics and Electronics, Georgia Institute of Technology; Atlanta Georgia 30332-0400 USA
2. Universidade de Brasilia, Instituto de Física; Brasilia DF 70919-970 Brazil
3. Laboratoire de Physicochimie des Polymères et des Interfaces (LPPI); Université de Cergy-Pontoise; 5 Mail Gay-Lussac F-95031 Cergy-Pontoise Cedex France
4. Department of Chemistry; Faculty of Science, King Abdulaziz University; Jeddah 21589 Saudi Arabia