Zinc and chloroindium complexes of furan-2-ylmethoxy substituted phthalocyanines: Preparation and investigation of aggregation, singlet oxygen generation, antioxidant and antimicrobial properties

Abstract

Abstract The synthesis, characterization, aggregation, photophysical, antioxidant and antimicrobial properties of furan-2-ylmethoxy substituted zinc (2) and chloroindium (3) phthalocyanine complexes are reported for the first time. The novel compounds have been characterized by using elemental analysis, UV–vis, FT-IR, 1H-NMR and MS spectroscopic data. In photophysical studies, the effect of the central metal ion on the UV–vis and photophysical properties of the metallophthalocyanines are reported. These results suggest that the metal in the core of the phthalocyanine plays essential role in the fluorescence quantum yields (ΦF) of the synthesized complexes. In addition, high quantum yields of singlet oxygen generation (ΦΔ ranging from 0.58 to 0.69 in THF) were obtained. Antioxidant activities of the complexes were determined by using three different methods. In all experiments performed, complex 3 showed better antioxidant activity than complex 2. Complex 3 showed 59.01 ± 1.23% inhibition of DPPH (1,1-diphenyl-2-picrylhydrazyl) free radicals and 84.16 ± 0.13% ferrous metal chelating activity both at 500 mg/L concentration and the highest reducing power activity were measured at 0.397 nm with 80 mg/L concentration. Inhibition zone of complex 3 was found as 11 mm for Escherichia coli, 7.5 mm for Bacillus subtilis, 13 mm for Bacillus cereus and 9 mm for Pseudomonas aeruginosa. Inhibition zone of complex 2 was found 8 mm for Staphylococcus aureus and Bacillus subtilis (ATCC 6051). In addition, MIC (Minimum Inhibitory Concentrations) values varied in the range of 2.0–64 μg/mL.