1. Department of Chemistry; Dalhousie University; Halifax Nova Scotia B3H 4R2 Canada
2. Department of Chemistry and Biochemistry; Brigham Young University; Provo UT 84602 USA
3. X-ray Crystallography Laboratory; Department of Chemistry University of Alberta; Edmonton Alberta T6G 2G2 Canada
4. Research and Technology; Chevron Phillips Chemical Company LP; 1862 Kingwood Drive Kingwood TX 77339 USA