Homoleptic metal complexes derived from hydrazones as ligand; synthesis, cytotoxic activity, photoluminescence properties and ADMET studies

Abstract

In the present work, N'-(2‑hydroxy-5-nitrobenzylidene)thiophene-2-carbohydrazide (L) and its Cu(II), Ni(II), Co(II), and Fe(II) complexes have been prepared. Their chemical structures were characterized by elemental analysis, molar conductivity, FT-IR, UV–Vis, TGA, LC-MS/MS, 1H and 13C NMR (for ligand). Also, the photoluminescence properties of the free ligand and its metal complexes were investigated in DMF solution. The ligand is emissive at 430–630 nm range and the emission band is almost turned off upon complexation with Cu(II) and Fe(II) ions. Emission spectra of the Ni(II) and Co(II) complexes showed a blue shift compared to the free ligand. Also, in vitro cytotoxic activities of both ligand and its metal complexes against HTB-54 and BEAS-2B cells have been investigated. The [Fe(L)2]⋅2H2O complex (IC50 35.59 μM) showed better cytotoxic activity than cisplatin against HTB-54 cells. Moreover, the ligand and its Fe(II) complex had slight cytotoxic activity against BEAS-2B cell line.