1. Department of Chemistry , Faculty of Science, Beirut Arab University , P.O. Box 11 50 20, Riad El Solh, 1107 2809 , Beirut , Lebanon
2. Department of Chemistry , Faculty of Science, Beirut Arab University , P.O. Box 11 50 20, Riad El Solh, 1107 2809 , Beirut , Lebanon , Tel.: +961 76977590 Ext: 3305
3. Chemistry Department, Faculty of Science , King Faisal University , Al-Ahsa 31982 , Saudi Arabia