title: Structure investigation of three hydrazones Schiff's bases by spectroscopic, thermal and molecular orbital calculations and their biological activities.
abstract: Three Schiff's bases AI (2(1-hydrazonoethyl)phenol), AII (2, 4-dibromo 6-(hydrazonomethyl)phenol) and AIII (2(hydrazonomethyl)phenol) were prepared as new hydrazone compounds via condensation reactions with molar ratio (1:1) of reactants. Firstly by reaction of 2-hydroxy acetophenone solution and hydrazine hydrate; it gives AI. Secondly condensation between 3,5-dibromo-salicylaldehyde and hydrazine hydrate gives AII. Thirdly condensation between salicylaldehyde and hydrazine hydrate gives AIII. The structures of AI-AIII were characterized by elemental analysis (EA), mass (MS), FT-IR and (1)H NMR spectra, and thermal analyses (TG, DTG, and DTA). The activation thermodynamic parameters, such as, ΔE(∗), ΔH(∗), ΔS(∗) and ΔG(∗) were calculated from the TG curves using Coats-Redfern method. It is important to investigate their molecular structures to know the active groups and weak bond responsible for their biological activities. Consequently in the present work, the obtained thermal (TA) and mass (MS) practical results are confirmed by semi-empirical MO-calculations (MOCS) using PM3 procedure. Their biological activities have been tested in vitro against Escherichia coli, Proteus vulgaris, Bacillissubtilies and Staphylococcus aurous bacteria in order to assess their anti-microbial potential.
authors.affiliation: Chemistry Department, Faculty of Science, Port Said University, Egypt.
authors.forename: Arafa A M
authors.initials: AA
authors.lastname: Belal
authors.affiliation: Chemistry Department, Faculty of Science, Cairo University, 12613, Egypt. Electronic address: mazayed429@yahoo.com.
authors.forename: M A
authors.initials: MA
authors.lastname: Zayed
authors.affiliation: Nuclear Physics Department, Nuclear Research Center, AEA, 13759 Cairo, Egypt.
authors.forename: M
authors.initials: M
authors.lastname: El-Desawy
authors.affiliation: Chemistry Department, Faculty of Science, Port Said University, Egypt.
authors.forename: Sh M A H
authors.initials: ShM
authors.lastname: Rakha
mesh_terms: D000900:Anti-Bacterial Agents / Q000737:chemistry* / Q000494:pharmacology*; D001419:Bacteria / Q000187:drug effects; D001424:Bacterial Infections / Q000188:drug therapy; D004055:Differential Thermal Analysis; D006801:Humans; D006835:Hydrazones / Q000737:chemistry* / Q000494:pharmacology*; D009682:Magnetic Resonance Spectroscopy; D008958:Models, Molecular; D015394:Molecular Structure; D012545:Schiff Bases / Q000737:chemistry* / Q000494:pharmacology*; D017550:Spectroscopy, Fourier Transform Infrared; D013816:Thermodynamics; D013818:Thermogravimetry
chemical_list: D000900:Anti-Bacterial Agents; D006835:Hydrazones; D012545:Schiff Bases
keywords: Biological activity; Molecular orbital calculation; Novel Schiff’s bases; Spectroscopic investigation; Thermal analyses