1. Department of Chemistry and Biochemistry, Ohio University, Athens, Ohio 45701, Nanotechnology Research Institute, Advanced Industrial Science and Technology (AIST), Tsukuba, Ibaraki 305-8565, Japan, Department of Physics and Astronomy, Ohio University, Athens, Ohio 45701, Department of Chemistry, University of Arkansas at Little Rock, Little Rock, Arkansas 72204, and DuPont Central Research and Development, Experimental Station, Wilmington, Delaware 19898