1. Department of Basic Engineering Science and Humanities, Netaji Subhash Engineering College, Panchpota, Garia, Kolkata-700 152, India
2. Department of Chemistry, Jalpaiguri Government Engineering College, Jalpaiguri-735 102, West Bengal, India
3. A. P. C. Roy Government College, Matigara, Siliguri-734010, West Bengal, India
4. Università degli Studi di Parma, Dipartimento di Chimica, Parco Area delle Scienze 17/A, I-43123 Parma, Italy
5. Department of Chemistry, Jalpaiguri Government Engineering College, Jalpaiguri-735 102, West Bengal, India , Tel.: +91-9433261720, Fax: +91 3561 256143