1. Department of Chemistry, University of Agriculture, Faisalabad 38000, Pakistan
2. Department of Chemistry, College of Science, King Saud University, P. O. Box 2455, Riyadh 11451, Saudi Arabia
3. Department of Chemistry, AN-Najah National University, P. O. Box 7, Nablus, Palestine
4. Chemistry Department, Faculty of Science, Minia University, Minia 61519, Egypt
5. School of Health Sciences, University of KwaZulu-Natal, Westville Campus, Durban 4000, South Africa
6. School of Chemistry and Chemical Engineering, Beijing Institute of Technology, Beijing 100081, P. R. China