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

Peripheral ( LuPc(p) ) and non-peripheral ( LuPc(np) ) derivatives of lutetium (III) mono-phthalocyanines and peripheral analogue of lutetium (III) bis-phthalocyanine ( LuPc 2 ) substituted with 3,4-(methylendioxy)-phenoxy have been synthesized and characterized by elemental analysis, FT-IR, UV–vis spectroscopy, and mass spectroscopy. Electrochemical and spectroelectrochemical analyses of the complexes were performed in solution. While LuPc(p) and LuPc(np) gave common Pc ring-based electron transfer processes, ring-to-ring interaction of LuPc 2 completely altered the redox behaviors of the complex. The first reduction reaction of LuPc 2 was recorded even at positive potentials, while the LuPc(p) and LuPc(np) gave this reduction reaction at around −1.00 V. Due to the π – π interaction of phthalocyanine rings around the lutetium core of LuPc 2 , a very narrow Δ E 1/2 (0.50 V) was recorded. LuPc 2 illustrated distinct color differences between the electrogenerated anionic and cationic forms of the complex, while LuPcs did not give obvious color changes.