1. Institute of Technical Chemistry, Leibniz University of Hannover, Callinstrasse 5, 30167 Hannover, Germany
2. Department of Basic and Supporting Sciences, Faculty of Pharmacy, Arab International University, 20872 Damascus, Syria
3. Physics Department, Faculty of Science, Damascus University, 20872 Damascus, Syria
4. Institute of Organic Chemistry, Leibniz University of Hannover, Schneiderberg 1B, 30167 Hannover, Germany