1. Department of Chemistry, University of Nevada, Las Vegas, Nevada 89154-4003, USA
2. Advanced Light Source, Lawrence Berkeley National Laboratory, Berkeley, California 94720, USA
3. Instituto de Física, Universidade Federal do Rio de Janeiro, Caixa Postal 68525, 21941-972 Rio de Janeiro, RJ, Brazil
4. Instituto de Química, Universidade Federal do Rio de Janeiro, 21949-900 Rio de Janeiro, RJ, Brazil
5. Department of Chemistry, University of Waterloo, Waterloo, Ontario N2L 3G1, Canada