title: Covalent Modification of Highly Ordered Pyrolytic Graphite with a Stable Organic Free Radical by Using Diazonium Chemistry.
abstract: A novel, persistent, electrochemically active perchlorinated triphenylmethyl (PTM) radical with a diazonium functionality has been covalently attached to highly ordered pyrolytic graphite (HOPG) by electrografting in a single-step process. Electrochemical scanning tunneling microscopy (EC-STM) and Raman spectroscopy measurements revealed that PTM molecules had a higher tendency to covalently react at the HOPG step edges. The cross-section profiles from EC-STM images showed that there was current enhancement at the functionalized areas, which could be explained by redox-mediated electron tunneling through surface-confined redox-active molecules. Cyclic voltammetry clearly demonstrated that the intrinsic properties of the organic radical were preserved upon grafting and DFT calculations also revealed that the magnetic character of the PTM radical was preserved.
authors.affiliation: Institut de Ciència de Materials de Barcelona (CSIC), and CIBER-BBN, Campus de la UAB, 08193, Bellaterra, Spain.
authors.forename: Gonca
authors.initials: G
authors.lastname: Seber
authors.affiliation: Department of Chemistry and Biochemistry, University of Bern, Freistrasse 3, 3012, Bern, Switzerland.|A.N. Frumkin Institute of Physical Chemistry and, Electrochemistry RAS, Leninskii pr.31, Moscow, 119991, Russia.
authors.forename: Alexander V
authors.initials: AV
authors.lastname: Rudnev
authors.affiliation: Nano-Bio Spectroscopy Group and European Theoretical, Spectroscopy Facility (ETSF), Universidad del País Vasco, Av. Tolosa 72, 20018, San Sebastian, Spain.
authors.forename: Andrea
authors.initials: A
authors.lastname: Droghetti
authors.affiliation: Materials Division, National Physical Laboratory, Teddington, TW11 0LW, UK.
authors.forename: Ivan
authors.initials: I
authors.lastname: Rungger
authors.affiliation: Institut de Ciència de Materials de Barcelona (CSIC), and CIBER-BBN, Campus de la UAB, 08193, Bellaterra, Spain.
authors.forename: Jaume
authors.initials: J
authors.lastname: Veciana
authors.affiliation: Institut de Ciència de Materials de Barcelona (CSIC), and CIBER-BBN, Campus de la UAB, 08193, Bellaterra, Spain.
authors.forename: Marta
authors.initials: M
authors.lastname: Mas-Torrent
authors.affiliation: Institut de Ciència de Materials de Barcelona (CSIC), and CIBER-BBN, Campus de la UAB, 08193, Bellaterra, Spain.
authors.forename: Concepció
authors.initials: C
authors.lastname: Rovira
authors.affiliation: Institut de Ciència de Materials de Barcelona (CSIC), and CIBER-BBN, Campus de la UAB, 08193, Bellaterra, Spain.
authors.forename: Núria
authors.identifier: http://orcid.org/0000-0001-6538-2482
authors.initials: N
authors.lastname: Crivillers
keywords: diazonium compounds; electrochemistry; radicals; redox chemistry; surface chemistry