Syntheses, Spectral, DNA Binding Studies of New Family of Copper (II) / Pentadentate SNNNS Schiff's Bases Complexes

This research focuses on new type of pentadentate ligand[ N3S2], which received great interest as a chelating ligand in coordination chemistry, and synthesis of its Cu(II) complexes. In part one, new pentadentate Schiff bases (E)-N1-((5bromothiophen-2-yl) methylene)-N2-(2-((E)-((5-bromothiophen-2yl) methylene) amino) ethyl)-ethane-1,2-diamine was prepared through one step reaction by mixing of 5-bromothiophene-2-carbaldehyde with diethylenetriamine without solvent. The characteristics of the ligand were determined by several techniques like: UV-Vis, MS, DFT, EA, SEM, EDS, NMR, IR and TG/DTG. The Cu(II) complexes 1 and 2 with general formula [CuN3S2]X2 where X: (Cl, Br) were prepared by mixing the ligand with CuX2 salt, X = Br, Cl. These complexes showed square pyramidal structure around the Cu(II) center. Several analytical techniques were performed for these complexes: Solvatochromism, TG/ DTG UV-Vis, MS, DFT, EA, SEM, EDS, NMR, IR and CV. In part two, another new pentadentate ligand (E)-N1-((5-bromothiophen-2-yl) methylene)-N2-(2-((E)-((5-bromothiophen-2- yl) methylene) amino) ethyl) ethane-1,2-diamine was prepared by the same procedure , mixing of 5 -bromothiophene-2-carbaldehyde with dipropylenetriamine, the product was characterized by : UV-Vis, MS, DFT, EA, SEM, EDS, NMR, IR,and TG/DTG. Complexes 3 and 4 were formed through mixing N3S2 with Cu(II) salt, the properties of the complexes were determined by TG/ DTG UV-Vis, MS, DFT, EA, SEM, EDS, NMR, IR and CV. The CT-DNA binding affinity of complexes 1 and 2 were evaluated by two methods: absorption spectroscopy, titration in both UV and visible regions, viscosity technique was also performed to support the results.