SELF-ASSEMBLY OF PHOTOLUMINESCENT COPPER(I)-DITHIOL MULTILAYER THIN-FILMS AND BULK MATERIALS

Self-assembled multilayer thin films have been prepared on Au and merc aptosilanized glass substrates by alternate surface derivatization wit h Cu2+ ion and alkanedithiols. The films deposited on glass show intri nsic orange-red photoluminescence and were studied by fluorescence spe ctroscopy. A strongly photoluminescent solid was also obtained by reac tion of 1,6-hexanedithiol with cupric perchlorate in ethanolic solutio n. Multilayer structures on Au were studied by ellipsometry and X-ray photoelectron spectroscopy (XPS). Both in the solid material and in th e self-assembled thin films, XPS measurements suggest Cu is present in the +1 oxidation state. This was also confirmed by cyclic voltammetry of Cu ion adsorbed to a self-assembled monolayer of 1,6-hexanedithiol on gold. Metal-metal interactions in the form of clustering might con tribute to the unusual photophysical properties observed in both types of materials.