SPECTROSCOPIC AND ELECTROCHEMICAL CHARACTERIZATION OF LANGMUIR-BLODGETT-FILMS OF TAKIS-((2-BENZYLOXY)ETHOXY)PHTHALOCYANINATO)COPPER AND ITSMETAL-FREE ANALOG

Spectroscopic, electrochemical and spectroelectrochemical, and scannin g probe microscopic characterization of thin films of takis((2-benzylo xy)ethoxy)phthalocyaninato)copper, and its dihydrogen analogue, in con tact with aqueous electrolytes is described. These materials form high ly ordered Langmuir-Blodgett (LB) thin films, where the phthalocyanine (Pc) rings orient with the plane of the ring nearly perpendicular to the compression direction on the LB trough. The resultant thin films s how remarkable mechanical stability on the trough, and atomic force mi croscopy studies show that the transferred thin films, in their fully compressed states, consist of stable bilayers of the Pc. X-ray diffrac tion studies indicate partial overlap of the benzyl-terminated side ch ains in adjacent Pc columns. While the DMF solution electrochemical be havior of these molecules showed a single quasi-reversible oxidation p rocess, LB thin films showed two poorly resolved oxidation processes. Two electrochemically distinct domains in these thin films are indicat ed, which are a function of the aggregation behavior of these material s, and result from electrochemically driven changes in film morphology .