TY - BOOK AU - Heba Mohamed Fahmy Abdelhakim AU - Abdelfatah M . Badawi , AU - Hussein M. A. Mustafa , TI - Theoretical and experimental investigation of 1, 3 , 4, - thiadiazole derivatives and their biological activity / PY - 2011/// CY - Cairo : PB - Heba Mohamed Fahmy Abdelhakim , KW - DFT KW - Thiadiazole derivatives KW - UV spectra N1 - Thesis (M.Sc.) - Cairo University - Faculty of Science - Department of Physical Chemistry; Issued also as CD N2 - The present work presents a detailed and through investigation of the electronic structure spectra and biological activity of some 1,3,4,- thiadiazole derivatives . Full geometry optimizations were performed at the DFT level of theory . The B3LYP method has been adopted . The effect of substituent's of different electron - donating (accepting) stregths on the geometry and the electronic structural features of 1,3,4,- thiadiazole was examined ER -