1. Department of Chemistry, Faculty of Science University of Lucknow Lucknow 226007 India
2. Department of Chemistry Dr. Ram Manohar Lohiya Avadh University Ayodhya 224001 India
3. Materials and Chemical Characterisation Facility MC2 University of Bath Bath BA2 7AY UK
4. Department of Chemistry, Sri Venkateswara College University of Delhi Delhi 110021 India