... El-Sayed M. MABROUK*, Hamada M. KILLA, Abdel Fattah A. Abdel FATTAH and Shalaby A. YASEN Chemistry Department, Faculty of Science, Zagazig University Zagazig, Egypt Receiked October 10, 1990 Accepted April 1, 1991 ... Collect. Czech. Chem. ... (Vol. 57) (1992) Page 8. ...