1. Department
of Chemistry, University of Calcutta, 92,
A. P. C. Road, Kolkata
700 009, India
2. Department
of Chemistry, Panchokot Mahavidyalaya,
Purulia, India
3. Department
of Inorganic Chemistry, Indian Association for the Cultivation of Science,
Jadavpur, Kolkata 700 032, India
4. Department of Chemistry, Jadavpur University, Jadavpur, Kolkata 700 032, India
5. Dipartimento di Scienze Chimiche
e Farmaceutiche, University of Trieste,
Via L. Giorgieri 1, 34127 Trieste, Italy