Preparation of Bis(phthalocyaninato)lutetium with Various Substituts and Their Electochemical Properties

Article abstract of DOI:10.1246/bcsj.65.250

A series of bis(phthalocyaninato)lutetium complexes with substituents on each benzoring 2R₈)> was prepared and the electrochromic behavior investigated by means of cyclic voltammetry of coated electrodes.Although the unsubstituted complex, Lu(pc)₂, showed multistep electrochromism, its stability was quite unsatisfactory due to a falling-off of films from the electrode surface upon repetitive potential scanning.In the case of R=t-butyl, the improved solubility in organic solvents brought about an easier filming process and better adhesion to the electrode surface, though its high oxidation potential caused a cleavage of bi-peripheral complex.In contrast, complexes with electron-donating groups, such as R = propoxy or neopentyloxy, showed a lower oxidation potential and better stability upon repetitive scans, though the oxidized color was brownish rather than bright red.Complexes with 4 groups each of tetra-t-butyl and tetra propoxy had the oxidation potential close to that of octapropoxy or octakis(neopentyloxy) complexes and showed much improved stability and electrochromic behavior.