1. Chemistry Department, Faculty of Science, Minia University, 61519 El-Minia, Egypt
2. Organic Chemistry Department, Faculty of Pharmacy, Al-Azhar University, 71526 Assiut, Egypt
3. Department of Medicinal Chemistry, Faculty of Pharmacy, Minia University, 61519-El-Minia, Egypt
4. Institute of Organic Chemistry, Karlsruhe Institute of Technology, Fritz-Haber-Weg 6, 76131 Karlsruhe, Germany
5. Chemistry Department, Florida Institute of Technology, Melbourne, FL 32901, USA
6. Laboratory of Inorganic Chemistry, Department of Chemistry, University of Helsinki, PO Box 55 (A.I. Virtasenaukio I), 00014 Helsinki, Finland