1. Department of Chemistry, Indian Institute of Technology Guwahati; Near Doul Gobinda Road, Amingaon, North Guwahati Guwahati, 781039 India
2. Department of Chemistry; St. Joseph's College; Devagiri Calicut 673008 India
3. Kent State University; Liquid Crystal Institute and Chemical Physics Interdisciplinary Program; Kent OH 44242 USA