1. Department
of Chemistry, National University of Singapore, 3 Science Drive 3, 117543 Singapore
2. Spectroscopy
Laboratory for Functional π-Electronic Systems and Department
of Chemistry, Yonsei University, Seoul 120-749, Korea
3. Department of Materials Science & Engineering, National University of Singapore, 119260 Singapore
4. Division
of Physical Science and Engineering and KAUST Catalysis Center, King Abdullah University of Science and Technology (KAUST), Thuwal 23955-6900, Kingdom of Saudi Arabia