ELECTRO-CHEMISTRY AND PHOTOCHEMISTRY OF 13-MEMBERED AZOCROWNS IN SOLUTION AND AS LANGMUIR-BLODGETT-FILMS

Electrochemical and photochemical investigations of amphiphilic 13-mem bered azobenzene crowns have shown that, in solution, Z <-> E isomeriz ation takes place for both the free crown ether and also for complexes with metal ions. Evidence for the formation of a new 1:2 (ligand:Na+) complex is presented. Monolayer Langmuir-Blodgett (LB) films on indiu m-tin oxide electrodes exhibited a stable voltammetric response corres ponding to the cis isomer. Significant differences were found for both the photochemical behavior and the ion selectivity between the soluti on and solid phases. Some indications of electrochemcial recognition o f Na+ were found for some LB films. This was evident from a shift in t he voltammetric potentials and in the peak current versus scan rate de pendence.