1. Department of Chemistry, Vivekananda Mission Mahavidyalaya, Chaitanyapur, Haldia-721645, India
2. Department of Chemistry and Biochemistry, University of Oklahoma, 620 Parrington Oval, Room 208, Norman, Oklahoma 73019-3051 USA
3. Department of Chemistry, University of Missouri-Kansas City, 5110 Rockhill Rd., Kansas City, MO 64110-2446, USA