Double-decker lutetium phthalocyanine functionalized with 4-phenylthiazol-2-thiol moieties: Synthesis, characterization, electrochemistry, spectroelectrochemistry and electrochromism

In this study, the synthesis, spectral characterization, electrochemistry, spectroelectrochemistry and electrochromism of a novel double-decker lutetium phthalocyanine, bis-[2(3),9(10),16(17),23(24)-tetrakis-[2-(4-phenyl-2-thiazolyl)sulfanyl] phthalocyaninatolutetium(III), denoted as LuPc₂, is reported. The LuPc₂ synthesized in this study is unique, being the first thiazole-containing double-decker lutetium phthalocyanine complex published to date. The electrochemistry of LuPc₂ was used to support the proposed sandwich structure. A characteristic first reduction couple at 0.32 V indicated reduction of the radical Pc ring of LuPc₂. The other redox process indicated electron transfer reactions of each Pc ring, which is in harmony with other sandwich type Pc complexes. Distinct color changes of LuPc₂ in solution showed its possible use in the solid state as an electrochromic material; thus, the electrochromic responses were analyzed using a LuPc₂ film. Fast, stable and reversible electrochromic responses were observed with green to red color changes.