1. Department of Chemistry, Indian Institute of Technology Guwahati, Guwahati, Assam 781039, India
2. Assam Energy Institute Sivasagar, Centre of Rajiv Gandhi Institute of Petroleum Technology, Sivasagar, Assam 785697, India
3. Department of Chemistry, University of North Bengal, Raja Rammohunpur, Darjeeling, West Bengal 734013, India