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

O-Vanillin and ethylenediamine were used for the synthesis of N , N '-bis(O-vanillinidene)ethylenediamine (O-VEDH 2 ) Schiff base ligand, which was characterized by UV-visible and 1 H NMR spectroscopy. The Schiff base ligand O-VEDH 2 has been employed to synthesize novel [C 18 H 22 FeN 2 O 6 ]NO 3 ( 1 ) and C 18 H 16 CuN 2 O 5 ( 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 P 121/ n 1 (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 H 2 O 2 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 H 2 O 2 sensing properties. Both complexes are bound to Calf-thymus DNA by intercalation binding mode, and binding constants ( K b ) of complexes 1 and 2 are 3.77 × 10 3 and 1.49 × 10 4 M -1 , respectively.