Metal bisphosphonate multilayers of perylene and naphthalene bis(dicarboximide) derivatives on ITO substrate

Two phosphonate-terminated redox molecules, which are N,N′-bis(ethyl dihydrogen phosphate)-3,4,9,10-perylene bis(dicarboximide) (EPPI) and N,N′-bis(ethyl dihydrogen phosphate)-1,4,5,8-naphthalene(dicarboximide) (EPNI), are adsorbed on indium-tin-oxide (ITO) substrate pretreated with ZrOCl2. Multilayer films of Zr-EPPI and Zr-EPNI were grown layer-by-layer on the substrate by the subsequent treatment of alternate dipping into aqueous ZrOCl2 and EPPI or EPNI solution. The layer growth and electron transfer from ITO to the multilayer were investigated with UV–VIS absorption and cyclic voltammetry.