Darren R. Dunphy

TL;DR: In this article, a monochromatic X-ray photoelectron spectroscopy (XPS) was used for surface characterization of indium−tin oxide (ITO) thin films.

TL;DR: The electroactive integrated optical waveguide (EA-IOW), a single-mode planar waveguide coated with an ITO layer, is ∼10(4)-fold more sensitive to changes in absorbance occurring during electrochemical events versus asingle-pass transmission spectroelectrochemical experiment, as demonstrated by reduction of surface-adsorbed methylene blue.

TL;DR: In this paper, a multichannel spectrometer based on a single mode planar integrated optical waveguide and capable of measuring broad-band visible absorbance spectra of a weakly absorbing molecular film at a solid−liquid interface is reported.

Abstract: We review here the self-assembly, electrochemical and spectroelectrochemical properties of 2,3,9,10,16,17,23,24-octa(2-benzyloxyethoxy) phthalocyaninato copper (CuPc(OC2OBz)8), where terminal benzyl groups on the eight ethylene oxide side chains assist in forming unusually ordered, mechanically rigid thin films. New spectroscopic characterization of cast CuPc(OC2OBz)8 films is discussed in comparison with cast films of its metal-free analogue H2Pc(OC2OBz)8 and similar copper and dihydrogen phthalocyanines with benzyl — terminated triethylene oxide substituents, CuPc((OC2O)3Bz)8, and H2Pc((OC2O)3Bz)8, which do not demonstrate the same degree of ordering as CuPc(OC2OBz)8. AFM studies of horizontally transferred LB films of CuPc(OC2OBz)8 show column–column distances of ca 2.8 nm and confirm the high degree of ordering previously surmised from spectroscopic characterization of multilayer thin films. The oxidative electrochemistry of multilayer thin films prepared from these Pcs is strongly dependent on the chemical identity of the supporting electrolyte anion and on annealing of the thin films. Compliance of the films to counter-ion transport limits the extent of electrochemical doping. Preliminary studies of the oxidative electrochemistry of isolated CuPc(OC2OBz)8 aggregates (diluted into an electroinactive methyl arachidate thin film) on an electroactive, integrated optic waveguide (EA-IOW) are also presented. Monitoring the change in absorbance at 633 nm on the waveguide surface allows the determination of the onset potential for oxidation of the isolated aggregates, which appears to be less positive in potential versus that observed for multilayer Pc assemblies.