Synthesis, characterization, nucleic acid interaction and photoluminescence properties of (E)-(2-(2-hydroxybenzylidene)hydrazinyl)(pyridin-4-yl)methaniminium Mn(II), Co(II), Ni(II), Cu(II) and Zn(II) complexes

Five new metal complexes ML2 [Where, M = Mn(II), Co(II), Ni(II), Cu(II) and Zn(II) and L is (E)-(2-(2-hydroxybenzylidene)hydrazinyl)(pyridin-4-yl)methaniminium)] have been synthesized and characterized by elemental analysis, molar conductivity, magnetic moment and spectroscopy (UV–Vis, FT-IR and ESR) studies. The spectral data showed that ligand is tridentating coordination through azomethine nitrogen, methaniminium nitrogen and phenolic oxygen. DNA binding studies of transition metal complexes 1–5 were examined by electronic absorption spectroscopic techniques. All the metal complexes 1–5 have shown hypochromism. Photoluminescence activity of ligand L and its metal complexes 1–5 were carried out. The ligand L showed weak emission in π→π* and n→π* excitation. The complexes 1, 2 and 4 didn't exhibited noticeable emission in three different excitation, complex 3 showed enhanced emission in π→π* and n→π* excitation and complex 5 showed enhanced emission in LMCT.