Synthesis, characterization and theoretical calculations of aminophenol and aminopyridine derivative new azomethine compounds

In this study, eight new azomethine compounds (3a-3h) containing thiophene-aminophenol functionality and seven new azomethine compounds (5a-5g) bearing thiophene-aminopyridine functionality were synthesized in good yields by using the conventional heating and microwave assisted synthesis methods. The structures of the newly synthesized compounds were characterized by UV-Vis, FTIR, 1H and 13C NMR spectroscopic techniques and elemental analysis. The optimized molecular structures by the theoretical method, 1H and 13C NMR chemical shift values, UV-Vis spectroscopic parameters, HOMO-LUMO energies, Mulliken (MPA) and natural (NBO) atomic charges, molecular electrostatic potential (MEP) maps and solvent accessible surfaces (SAS) were calculated for all compounds by using DFT/B3LYP/6-311G(2d,p) approach. The theoretical spectroscopic features obtained by DFT calculations show a very good agreement with the experimental data. In addition, (3a-3h) were screened for their antibacterial activities against Bacillus cereus (NRRL-B3711), Bacillus subtilis (NRRL-B4378), Escherichia coli (NRRL-B3008), Staphylococcus aureus (ATCC-6538) and Salmonella typhimurium (ATCC-13311), while (5a-5g) were investigated for their antibacterial activities against Bacillus cereus (NRRL-B3711), Escherichia coli (NRRL-B3008), Listeria monocytogenes, Micrococcus luteus, Salmonella typhimurium (ATCC-13311) ve Staphylococcus aureus (ATCC-6538). The results show that investigated compounds have either moderately and good active, slightly active or inactive among the tested microorganisms.