الفهرس 
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Abstract
The aim of this thesis is to synthesize some novel azole and azine derivatives starting from easily obtainable 2-cyano-N-(6-methylbenzo[d]thiazol-2-yl)acetamide and N’-(1-(4-aminophenyl)ethylidene)-2-cyanoacetohydrazide. Therefore, the work has been divided into four parts: PART (I) 2-cyano-N-(6-methylbenzo[d]thiazol-2-yl)acetamide and N’-(1-(4-aminophenyl)ethylidene)-2-cyanoacetohydrazide were prepared, then reacted with different organic reagents to yield novel heterocyclic compounds. The chemical structures of the obtained compounds were elucidated via different spectroscopic techniques. PART (II): Biological Evaluation. The newly synthesized compounds were evaluated for their in vitro antibacterial activity against (Gram-positive: B. subtilis and S. aureus), (Gram-negative bacteria: E. coli and P. aeruginosa). They were also evaluated for their in vitro antifungal potential against (C. albicans). The results showed that most of our compounds have excellent antibacterial and antifungal activities. PART (III): Molecular Docking. Docking of the compounds was performed using crystallographic structure from protein data bank (PDB code 1kzn). According to the docking survey at the binding site of DNA gyrase, compounds 6, 19, 22, and 24 are potential inhibitors. Part (IV): Corrosion Measurements. Quantum studies. The outcome data showed that pyridine derivatives (36-38) inhibited the corrosion of X-65 steel through: - Adsorption of pyridine derivatives on X-65 steel surface through electrostatic interactions or accumulation over the substrate surface. - Electron donation from the HOMO to the empty 3-d orbital of iron, and electron acceptance from the fulfilled 3-d orbital to LUMO of inhibitor via back-donation process. So, according to the calculated quantum studies the order of probability of the pyridine derivatives increases as follow: (38), PYR-Cl < (36), PYR-H < (37), PYR-OCH3. Monte Carlo Simulation: Simulation of the adsorption process over the steel surface in both vacuum and simulated acidic solution showed that pyridine derivatives (36-38) tend to be parallel and flat to the steel surface and hence leads to their strong interaction probability with steel surface. Also, the values of the adsorption energy (Eads.) parameter show that the adsorption probability of the pyridine derivatives (36-38) over X-65 steel is more favorable. Electrochemical techniques: The pyridine derivatives (36-38) was evaluated as corrosion inhibitors for carbon steel in 1 M HCl as an aggressive media by various electrochemical techniques such as potentiodynamic polarization (PDP) and electrochemical impedance spectroscopy (EIS). The data obtained prove the expected theoretical data. SEM, EDX, and corrosion inhibition mechanism: The results of SEM and EDX techniques indicated that the molecules of pyridine inhibitor (37) formed a good protective film on the X-65 steel surface which isolates the surface from the aggressive environment.