1. Department of Chemistry, University of North Texas, 1155 Union Circle, #305070, Denton, Texas 76203-5017, United States
2. Department of Chemistry, University of Manitoba, Winnipeg, MB R3T 2N2, Canada
3. Department of Chemistry, University of Tennessee, 552 Buehler Hall, 1420 Circle Dr., Knoxville, Tennessee 37996-1600, United States