title: Pyrene-based dyad and triad leading to a reversible chemical and redox optical and magnetic switch.
abstract: Two new pyrene-polychlorotriphenylmethyl (PTM) dyads and triads have been synthesized and characterized by optical, magnetic, and electrochemical methods. The interplay between the different electronic states of the PTM moiety in the dyads and triads and the optical and magnetic properties of the molecules have been studied. The electronic spectra of the radicals 5(.) and 6(.) show the intramolecular charge-transfer transition at around 700 nm due to the acceptor character of the PTM radical. In the diamagnetic protonated derivatives 3 and 4 the fluorescence due to the pyrene is maintained, whereas in the radicals 5(.) and 6(.) and the corresponding anions 5(-) and 6(-) there is a clear quenching of the fluorescence, which is more efficient in the case of radicals. The redox activity of PTM radicals that are easily reduced to the corresponding carbanion has been exploited to fabricate electrochemical switches with optical and magnetic response.
authors.affiliation: Institut de Ciència de Materials de Barcelona (ICMAB-CSIC), Campus UAB, 08193 Bellaterra (Spain); Networking Research Center on Bioengineering Biomaterials and Nanomedicine (CIBER-BBN), 08193 Bellaterra (Spain).
authors.forename: Carlos
authors.initials: C
authors.lastname: Franco
authors.forename: Marta
authors.initials: M
authors.lastname: Mas-Torrent
authors.forename: Antonio
authors.initials: A
authors.lastname: Caballero
authors.forename: Arturo
authors.initials: A
authors.lastname: Espinosa
authors.forename: Pedro
authors.initials: P
authors.lastname: Molina
authors.forename: Jaume
authors.initials: J
authors.lastname: Veciana
authors.forename: Concepció
authors.initials: C
authors.lastname: Rovira
mesh_terms: D055664:Electrochemical Techniques; D004583:Electrons; D005453:Fluorescence; D054879:Halogenation; D008280:Magnetics; D008745:Methylation; D010084:Oxidation-Reduction; D011721:Pyrenes / Q000737:chemistry*
chemical_list: D011721:Pyrenes; C030984:pyrene
keywords: donor-acceptor systems; electronic states; molecular devices; radicals; redox chemistry