1. Department of Chemistry (Center of Advanced Study); Institute of Science; Banaras Hindu University; Varanasi 221005 India
2. Department of Chemistry (Mahila Maha Vidyalaya); Banaras Hindu University; Varanasi 221 005 India
3. Department of Chemical Sciences; Tata Institute of Fundamental Research; Homi Bhabha Road, Colaba Mumbai 400005 India
4. Department of Chemistry; Keene State College; 229 Main Street Keene, NH 03435-2001 USA