ELECTROCHROMISM IN SANDWICH-TYPE DIPHTHALOCYANINES - ELECTROCHEMICAL AND SPECTROSCOPIC BEHAVIOR OF BIS(PHTHALOCYANINATO)TITANIUM(IV) (TI(PC)(2)) FILM

Bis(phthalocyaninato) titanium(IV) (Ti(Pc)(2)) films deposited on a tr ansparent conductive electrode show a colour change upon electrochemic al oxidation in aqueous electrolyte; the film colour changes from yell ow to reddish-brown passing from the neutral to the di-oxidized form a nd from reddish-brown to green, to yellow again passing from the di-ox idized to the mono-oxidized and to the neutral form, respectively. The phenomenon is reversible and rapid, and the system seems to be intere sting for application. Cyclic voltammetry and square-wave pulse experi ments were analysed together with electronic spectra and X-ray photoel ectron spectroscopy (XPS) surface analysis.