title: Redox grafting of diazotated anthraquinone as a means of forming thick conducting organic films.
abstract: Thick conductive layers containing anthraquinone moieties are covalently immobilized on gold using redox grafting of the diazonium salt of anthraquinone (i.e., 9,10-dioxo-9,10-dihydroanthracene-1-diazonium tetrafluoroborate). This grafting procedure is based on using consecutive voltammetric sweeping and through this exploiting fast electron transfer reactions that are mediated by the anthraquinone redox moieties in the film. The fast film growth, which is followed by infrared reflection absorption spectroscopy, atomic force microscopy, X-ray photoelectron spectroscopy, ellipsometry, and coverage calculation, results in a mushroom-like structure. In addition to varying the number of sweeps, layer thickness control can easily be exerted through appropriate choice of the switching potential and sweep rate. It is shown that the grafting of the diazonium salt is essentially a diffusion-controlled process but also that desorption of physisorbed material during the sweeping process is essentially for avoiding blocking of the film due to clogging of the electrolyte channels in the film. In general, sweep rates higher than 0.5 V s(-1) are required if thick, porous, and conducting films should be formed.
authors.affiliation: Department of Chemistry, Aarhus University, Langelandsgade 140, DK-8000 Aarhus C, Denmark.
authors.forename: Antoine
authors.initials: A
authors.lastname: Bousquet
authors.forename: Marcel
authors.initials: M
authors.lastname: Ceccato
authors.forename: Mogens
authors.initials: M
authors.lastname: Hinge
authors.forename: Steen Uttrup
authors.initials: SU
authors.lastname: Pedersen
authors.forename: Kim
authors.initials: K
authors.lastname: Daasbjerg
mesh_terms: D000880:Anthraquinones / Q000737:chemistry*; D001391:Azo Compounds / Q000737:chemistry*; D018625:Microscopy, Atomic Force; D010084:Oxidation-Reduction; D056951:Photoelectron Spectroscopy
chemical_list: D000880:Anthraquinones; D001391:Azo Compounds