1. Department of Chemistry, College of Science, King Faisal University, Al-Ahsa 31982, Saudi Arabia
2. Department of Chemistry, Faculty of Science, University of Khartoum, Khartoum 11114, Sudan
3. Department of Chemistry, College of Science, Sultan Qaboos University, P.O. Box 36, Al-Khoud 123, Oman
4. Department of Chemical Laboratories, College of Science, Sudan University of Science and Technology, Khartoum 11115, Sudan