1. Department of Chemistry, Jadavpur University, Kolkata 700 032, India
2. Department of Physics, M. G. Mahavidyalaya, Bhupatinagar, Midnapore (East),
West Bengal 721 425, India
3. School of Chemistry, The University of Manchester, Brunswick Street, Manchester,
M13 9PL, United Kingdom
4. Departament de Química, Universitat de les Illes Balears, Crta. de Valldemossa
km 7.5, 07122 Palma (Baleares), Spain