Alkyl chain modified metalophthalocyanines with enhanced antioxidant-antimicrobial properties by doping Ag+ and Pd2+ ions

Abstract

In this study, we report the synthesis and characterization of peripheral alkyl chain-substituted metalophthalocyanines [CuPc (3), ZnPc (4), and CoPc (5)] as optically sensitive substances with antifungal and antibacterial properties. Synthesized compounds were characterized by using common spectroscopic methods such as 1H NMR, 13C NMR, FT-IR, MALDI-TOF, fluorescence, and UV–Vis spectroscopy. Aggregation behaviors of phthalocyanines in the presence of Ag+ and Pd2+ ions were investigated by UV–Vis and fluorescence spectroscopy. The quenching capacity of Ag+ and Pd2+ ions for (4) was calculated from the Stern-Volmer equation and was found to be 9.76 × 104 mol/L and 2.86 × 105 mol/L for Pd2+ and Ag+ ions, respectively. The binding stoichiometry (n) and binding constant (Ka) of (4) for Ag+and Pd2+ions were calculated by the changed Benesi-Hildebrand equation. Ka value of (4) for Ag+and Pd2+ions are 2.57 × 109M − 1 and 1.44 × 108M − 1, respectively. The binding ratio of (4) for Ag+and Pd2+ions is 1.83 and 1.68, respectively. The morphological features of phthalocyanine derivatives were examined before and after the Ag+or Pd2+ions treatment by scanning electron microscopy (SEM). In addition, the antioxidant efficiencies of newly synthesized metalophthalocyanines and their Ag+ and Pd2+ ion-doped aggregates were evaluated using different methods such as DPPH free radical scavenging, iron ion chelating, and reducing power activities. The chemical and biological activities of phthalonitrile and its metalophthalocyanines were also evaluated by DFT and molecular docking calculations. Finally, the antifungal and antibacterial efficiencies of newly synthesized β-substituted phthalocyanines and their Ag+ and Pd2+ ion-doped forms were investigated using macrobroth dilution and disk diffusion methods.