1. Research and Development Centre, Bharathiar University, Coimbatore, Tamil Nadu, India;
2. Sri Ranganathar Institute of Engineering and Technology, Coimbatore, India;
3. Department of Chemistry, V. O. Chidambaram College, Tuticorin, Tamil Nadu, India;
4. Department of Chemistry, Arignar Anna Government Arts College, Cheyyar, Tiruvannamalai, Tamil Nadu, India