The teoretical i?nvestigation of geometrical, electronic and spectroscopic properties of some schiff bases C12H18ClN3OS and C11H15ClN4S molecules

In this study electronic and Spectroscopic property of some Schiff bases 2-amino-6-(N-isopropyl) amidino-2-methylbenzothiazole hydrochloride (C12H18ClN3OS) and 2-amino-6-(N-isopropyl)amidinobenzothiazole hydrochloride (C11H15ClN4S) molecules have been investigated by using Gauss-View and Gauss 03 package program. The molecular structure of C12H18ClN3OS and C11H15ClN4S molecules at ground state have been found by HF, B3LYP and BLYP methods. The stable states of the molecules have been found by using geometrical optimization and the bond length and bond angles were calculated by using 6-31G, 6-31G+, 6-31G++ and 6-31G++(d,p) basic sets. The infrared vibration frequencies and 1H and 13C NMR chemical shift values of these molecules were theoretically calculated. Obtained theoretical values were compared with experimental data. The most probable full molecular orbital energy states (?HOMO, eV), the least probable empty orbital molecular orbital energy states ((?LUMO, eV) have been investigated using HF and B3LYP and BLYP methods with 6-31G, 6-31/G+, 6-31G++ and 6-31G++(d,p) basic sets at 12 different sets at stable state. The hardness (?) and electro negativity (?) parameters were determined taking into account these energy values. It was observed that theoretical and experimental values were in a good agreement within the uncertainty limits.