1. Department of Chemistry and Biochemistry, University of Texas at Arlington, Arlington, Texas 76019, United States
2. Department of Chemistry, Texas A & M University, College Station, Texas 77843, United States
3. Department of Chemistry and Biochemistry, Bates College, Lewiston, Maine 04240, United States
4. Department of Chemistry and Biochemistry, University of Northern Colorado, Greeley, Colorado 80639, United States