1. Department of Chemistry, Inorganic Section, Jadavpur University, Kolkata 700032, India
2. Department of Physics, Jadavpur University, Kolkata 700032, India
3. Department of Higher Education, (University Branch) Government of West Bengal,BikashBhavan, Salt Lake, Kolkata-91, India
4. Departament de Química, Universitat de les Illes Balears, Crta de valldemossa km 7.7, 07122 Palma de Mallorca (Baleares), Spain
5. School of Chemistry, The University of Reading, P.O. Box 224, Whiteknights, Reading RG6 6AD, UK