GAZI UNIVERSITY JOURNAL OF SCIENCE, cilt.30, sa.1, ss.191-214, 2017 (ESCI)
In this work, two nitro-Schiff bases were synthesized by condensation reaction of 4-nitrobenzaldehyde with p-phenylenediamine and 3-amino-2-naphthol in 2: 1 and 1: 1 ratios, respectively. Then, the reduction of nitro group to amino group with sodium dithionite and forming the new imine bond by adding aldehyde, as salicylaldehyde, 2-hydroxy-1-naphthaldehyde or terephthaldehyde, asymmetric tetraimine Schiff bases (L-1, L-2, L-3) were prepared. Tetraimines have been characterized by elemental analysis, FT-IR, H-1/C-13 NMR, UVVis, and mass spectroscopy techniques in order to study the structure effect on the phenol-keto tautomerism. Solvent, acid and base effects on the tautomeric equilibrium have been also investigated by using UV-Vis spectra.