title: Tailoring Colors by O Annulation of Polycyclic Aromatic Hydrocarbons.
abstract: The synthesis of O-doped polyaromatic hydro- carbons in which two polycyclic aromatic hydrocarbon sub units are bridged through one or two O atoms has been achieved. This includes high-yield ring-closure key steps that, depending on the reaction conditions, result in the formation of furanyl or pyranopyranyl linkages through intramolecular C-O bond formation. Comprehensive photophysical measurements in solution showed that these compounds have exceptionally high emission yields and tunable absorption properties throughout the UV/Vis spectral region. Electrochemical investigations showed that in all cases O annulation increases the electron-donor capabilities by raising the HOMO energy level, whereas the LUMO energy level is less affected. Moreover, third-order nonlinear optical (NLO) measurements on solutions or thin films containing the dyes showed very good values of the second hyperpolarizability. Importantly, poly(methyl methacrylate) films containing the pyranopyranyl derivatives exhibited weak linear absorption and NLO absorption compared to the nonlinearity and NLO refraction, respectively, and thus revealed them to be exceptional organic materials for photonic devices.
authors.affiliation: Department of Chemical and Pharmaceutical Sciences, INSTM UdR Trieste, University of Trieste, Piazzale Europa 1, 34127, Trieste, Italy.|School of Chemistry, Cardiff University, Park Place, CF10 3AT, Cardiff, UK.
authors.forename: Tanja
authors.identifier: http://orcid.org/0000-0003-3893-7045
authors.initials: T
authors.lastname: Miletić
authors.affiliation: School of Chemistry, Cardiff University, Park Place, CF10 3AT, Cardiff, UK.|Department of Chemistry, University of Namur (UNamur), 61 Rue de Bruxelles, Namur, 5000, Belgium.
authors.forename: Andrea
authors.identifier: http://orcid.org/0000-0003-1080-0530
authors.initials: A
authors.lastname: Fermi
authors.affiliation: Department of Physics, University of Patras, 26504, Patras, Greece.|Institute of Chemical Engineering Sciences (ICE-HT), Foundation for Research and Technology-Hellas (FORTH), P.O. Box 1414, Patras, 26504, Greece.
authors.forename: Ioannis
authors.initials: I
authors.lastname: Orfanos
authors.affiliation: Institute of Biology, Medicinal Chemistry and Biotechnology, National Hellenic Research Foundation, 48 Vas. Constantinou Avenue, Athens, 11635, Greece.
authors.forename: Aggelos
authors.initials: A
authors.lastname: Avramopoulos
authors.affiliation: Department of Chemistry, University of Namur (UNamur), 61 Rue de Bruxelles, Namur, 5000, Belgium.
authors.forename: Federica
authors.identifier: http://orcid.org/0000-0001-8554-8507
authors.initials: F
authors.lastname: De Leo
authors.affiliation: Elettra-Sincrotrone Trieste, S.S. 14 Km 163.5 in Area Science Park, 34149, Basovizza-Trieste, Italy.
authors.forename: Nicola
authors.identifier: http://orcid.org/0000-0003-0288-3233
authors.initials: N
authors.lastname: Demitri
authors.affiliation: Department of Chemistry "Giacomo Ciamician", University of Bologna, Via Selmi 2, 40126, Bologna, Italy.
authors.forename: Giacomo
authors.identifier: http://orcid.org/0000-0002-2135-4073
authors.initials: G
authors.lastname: Bergamini
authors.affiliation: Department of Chemistry "Giacomo Ciamician", University of Bologna, Via Selmi 2, 40126, Bologna, Italy.
authors.forename: Paola
authors.identifier: http://orcid.org/0000-0001-8916-1473
authors.initials: P
authors.lastname: Ceroni
authors.affiliation: Institute of Biology, Medicinal Chemistry and Biotechnology, National Hellenic Research Foundation, 48 Vas. Constantinou Avenue, Athens, 11635, Greece.
authors.forename: Manthos G
authors.initials: MG
authors.lastname: Papadopoulos
authors.affiliation: Department of Physics, University of Patras, 26504, Patras, Greece.|Institute of Chemical Engineering Sciences (ICE-HT), Foundation for Research and Technology-Hellas (FORTH), P.O. Box 1414, Patras, 26504, Greece.
authors.forename: Stelios
authors.initials: S
authors.lastname: Couris
authors.affiliation: Department of Chemical and Pharmaceutical Sciences, INSTM UdR Trieste, University of Trieste, Piazzale Europa 1, 34127, Trieste, Italy.|School of Chemistry, Cardiff University, Park Place, CF10 3AT, Cardiff, UK.|Department of Chemistry, University of Namur (UNamur), 61 Rue de Bruxelles, Namur, 5000, Belgium.
authors.forename: Davide
authors.identifier: http://orcid.org/0000-0001-5717-0121
authors.initials: D
authors.lastname: Bonifazi
keywords: annulation; chromophores; doping; nonlinear optics; polycyclic aromatic hydrocarbons