1. Department of Chemistry and Biochemistry and the Liquid Crystal Materials
Research Center, University of Colorado, Boulder, Colorado 80309, United States
2. Chemical
and Materials Science Center, National Renewable Energy Laboratory, Golden, Colorado 80401, United States
3. Department
of Chemistry and Physics, Warren Wilson College, Swannanoa, North Carolina 28778, United States
4. Department of Physics and the Liquid Crystal
Materials Research Center, University of Colorado, Boulder, Colorado 80309, United States