Electrochemical Properties of a New Class of Europium Sandwich Triple-Decker Complexes with Corrole and Phthalocyanine Macrocycles

The electrochemical properties of a new class of sandwich (phthalocyaninato)(corrolato) europium triple-decker complexes were synthesized and characterized by cyclic voltammetry in CH₂Cl₂ containing 0.1 M tetrabutylammonium perchlorate (TBAP) as supporting electrolyte. Two of the compounds described in the current paper are shown in the figure, and represented by HEu₂[Pc(R)₈]₂[Cor(ClPh)₃], where R = OC₅H₁₁ or OC₈H₁₇, Pc represents the dianion of phthalocyanine and Cor represents the trianion of corrole. Both triple-decker complexes exhibit five reversible oxidations and three reversible reductions, all of which are attributed to ligand-based redox processes. The half-wave potentials for the first oxidation and first and second reduction of the two europium triple-deckers are close to E_1/2 values for the double-decker species Eu[Pc(OC₈H₁₇)₈]₂, while half-wave potentials for the second to fifth oxidations are close to E_1/2 values for the triple-decker Eu₂[Pc][Pc(OC₈H₁₇)₈]₂. The synthesis and electrochemical properties of the new compounds will be described.

Acknowledgment: This work was supported by the Natural Science Foundation of China (No. 21001054, 21071067) and the Robert A. Welch Foundation (K.M.K., Grant E-680).