Electrochemical and spectroelectrochemical properties of novel lutetium(III) mono- and bis-phthalocyanines

Peripherally and non-peripherally substituted mono and sandwich lutetium(III) phthalocyanines bearing 3,4-(dimethoxyphenylthio) substituents have been synthesized and characterized by elemental analysis, FT-IR, UV-vis spectroscopy and mass spectroscopy. Voltammetric, in-situ spectroelectrochemical, and in-situ electrocolorimetric characterization of the newly synthesized phthalocyanines were performed in solution. Changing the number and the position the substituents altered the reversibility of the electron transfer processes and affected the easy of electron transfer reactions. While the mono phthalocyanines had an oxidation-reduction peak separation (ΔE1/2) higher that 1.50 V, this value decreased up to 0.36 V due to the π-π interaction of phthalocyanine rings around the lutetium core. Solvent of the electrolytic system also affected the redox behaviors of the complexes considerably. In-situ electrocolorimetric method was applied to investigate the color of the electrogenerated anionic and cationic forms of the complexes for their possible electrochromic applications.