Synthesis, characterization and electrochemical properties of isoflavone substituted zinc(II), cobalt(II), and metal-free phthalocyanines

Abstract

In this study, novel tetrasubstituted metallo- and metal-free phthalocyanines containing 7-hydroxy-4′-methoxyisoflavonoxy moieties at peripheral and non-peripheral positions have been prepared by cyclotetramerization of corresponding phthalonitriles. The most obvious feature of these quaternized complexes is their extensive solubility and non-aggregated species (especially non-peripherally substituted) in organic solvents such as chloroform, tetrahydrofuran, dimethylformamide and dimethylsulfoxide, which makes them candidates for use in many applications in different fields. The new compounds have been characterized by elemental analysis, FT-IR, UV-vis, 1H and [Formula: see text]C NMR and MS (Maldi-TOF MS). Voltammetric and in situ spectroelectrochemical measurements have been performed with the aim of characterizing the electron transfer properties of the compounds on Pt in dimethylsulfoxide/tetrabutylammonium perchlorate, compared to those of previously reported corresponding compounds with tetra 6-hydroxyflavonoxy substituents. The effect of aggregation on the redox character of these complexes was also discussed.

Electrochemical and in-situ spectroelectrochemical behaviors of non-peripherally tetra substituted zinc(II) and magnesium(II) phthalocyanines

“…This result can be stemmed from electron-releasing character of 4-(4,5-diphenyl-4H-1,2,4-triazol-3-ylthio) substituent. It is well known that while more electron-donating substituents make more difficult reduction process and more easy oxidation process, more electron-releasing substituents make more easy reduction process and more difficult oxidation process (27). ΔEp values was calculated using a formula ΔEp = Epa-Epc =0.0592/n V, which is the criterion of theoretical reversibility (28).…”