title: NIR Electrofluorochromic Properties of Aza-Boron-dipyrromethene Dyes.
abstract: The photophysical properties of near-infrared (NIR) emissive aza-boron-dipyrromethene (aza-BDP) dyes incorporating nitrofluorene and alkoxy decorations were intensively investigated. Their highly reversible one-electron reduction process showed characteristic electrofluorochromic (EF) properties in the NIR range, depending on the substituents. The nitrofluorene ethynyl-substituted (Type I) dyes showed smaller EF effects than the alkoxy-containing (Type II) dyes because of the difference in their intrinsic fluorescence contrast between the neutral and reduced states (radical anion). In addition, the Type II chromophores showed a larger diffusion coefficient for ion transport, which enhanced the EF contrast and the response time for the fluorescence change at a given step potential. With an optimized condition, the NIR EF ON/OFF ratio reached a value of 6.1 and a long cyclability over 1000 EF cycles between -0.4 V and +0.4 V switching potentials, with approximately 20% loss of the initial ON/OFF switching ratio. The NIR EF switching was visually observed through a visible light cut-off filter, featuring high fluorescence contrast.
authors.affiliation: Department of Chemical and Biomolecular Engineering, Yonsei University, 50 Yonsei-ro, Seodaemun-gu, 120-749 Seoul, Republic of Korea.
authors.forename: Hanwhuy
authors.initials: H
authors.lastname: Lim
authors.affiliation: Department of Chemical and Biomolecular Engineering, Yonsei University, 50 Yonsei-ro, Seodaemun-gu, 120-749 Seoul, Republic of Korea.
authors.forename: Seogjae
authors.initials: S
authors.lastname: Seo
authors.affiliation: CNRS-UMR 5182, Ecole Normale Supérieure de Lyon, Université de Lyon1, 46 Allée d'Italie, 69007 Lyon, France.
authors.forename: Simon
authors.initials: S
authors.lastname: Pascal
authors.affiliation: CNRS-UMR 5182, Ecole Normale Supérieure de Lyon, Université de Lyon1, 46 Allée d'Italie, 69007 Lyon, France.
authors.forename: Quentin
authors.initials: Q
authors.lastname: Bellier
authors.affiliation: UMR 6226 CNRS-Université de Rennes 1, Institut des Sciences Chimiques de Rennes, 263 Av. du Général Leclerc, F-35042, Rennes Cedex, France.
authors.forename: Stéphane
authors.initials: S
authors.lastname: Rigaut
authors.affiliation: Department of Chemical and Biomolecular Engineering, Yonsei University, 50 Yonsei-ro, Seodaemun-gu, 120-749 Seoul, Republic of Korea.
authors.forename: Chihyun
authors.initials: C
authors.lastname: Park
authors.affiliation: Department of Chemical and Biomolecular Engineering, Yonsei University, 50 Yonsei-ro, Seodaemun-gu, 120-749 Seoul, Republic of Korea.
authors.forename: Haijin
authors.initials: H
authors.lastname: Shin
authors.affiliation: CNRS-UMR 5182, Ecole Normale Supérieure de Lyon, Université de Lyon1, 46 Allée d'Italie, 69007 Lyon, France.
authors.forename: Olivier
authors.initials: O
authors.lastname: Maury
authors.affiliation: CNRS-UMR 5182, Ecole Normale Supérieure de Lyon, Université de Lyon1, 46 Allée d'Italie, 69007 Lyon, France.
authors.forename: Chantal
authors.initials: C
authors.lastname: Andraud
authors.affiliation: Department of Chemical and Biomolecular Engineering, Yonsei University, 50 Yonsei-ro, Seodaemun-gu, 120-749 Seoul, Republic of Korea.
authors.forename: Eunkyoung
authors.initials: E
authors.lastname: Kim