1. Faculty of Science, Department of Chemistry, Alexandria University, Alexandria, Egypt
2. Department of Chemistry, Rabigh College of Science and Art, King Abdulaziz University, Rabigh, Saudi Arabia
3. Department of Chemistry, College of Science, King Saud University, Riyadh, Saudi Arabia
4. Graz University of Technology, Mandellstrasse 11 (III), A-8010, Graz, Austria