Synthesis of Two Mononuclear Schiff Base Metal (M = Fe, Cu) Complexes: MOF Structure, Dye Degradation, H2O2 Sensing, and DNA Binding Property.

Abstract

O-Vanillin and ethylenediamine were used for the synthesis of N,N′-bis(O-vanillinidene)ethylenediamine (O-VEDH2) Schiff base ligand, which was characterized by UV–visible and 1H NMR spectroscopy. The Schiff base ligand O-VEDH2 has been employed to synthesize novel [C18H22FeN2O6]NO3 (1) and C18H16CuN2O5 (2) complexes by the simple slow evaporation method. The single crystals were characterized by X-ray crystallography, as well as Fourier-transform infrared and UV–visible spectroscopy techniques. Complexes 1 and 2 crystallize in monoclinic and orthorhombic space groups with P121/n1 (14) and Pnma (62) point groups, respectively, and both show metal–organic frameworks like structures. Complexes 1 and 2 have optical band gaps of 4.1 and 2.9 eV, respectively, indicating their semiconducting properties. The dye degradation activity and H2O2 sensing of the complexes 1 and 2 were determined in different conditions. The photocatalytic test was performed in the presence of sunlight, methylene blue (MB), and complexes 1 and 2. An interesting result was obtained that complex 2 has degradation ability against MB and the rate constant (K) is 5.46 × 10–5 s–1, whereas complex 1 has H2O2 sensing properties. Both complexes are bound to Calf-thymus DNA by intercalation binding mode, and binding constants (Kb) of complexes 1 and 2 are 3.77 × 103 and 1.49 × 104 M–1, respectively.