title: Near-IR Absorbing J-Aggregate of an Amphiphilic BF2-Azadipyrromethene Dye by Kinetic Cooperative Self-Assembly.
abstract: A new amphiphilic BF2-azadipyrromethene (aza-BODIPY) dye 1 has been synthesized using a CuI-catalyzed "click" reaction. For this dye, two self-assembly pathways that lead to different type of J-aggregates with distinct near-infrared optical properties have been discovered. The metastable off-pathway product displays a broad, structureless absorption band while the thermodynamically stable on-pathway aggregate exhibits the characteristic spectral features of a J-aggregate, that is, red-shifted intense absorption band with significantly narrowed linewidth. The morphology and structure of the aggregates were studied by atomic force microscopy, transmission and scanning electron microscopy. The aggregation processes of 1 were investigated by temperature- and concentration-dependent UV/Vis spectroscopy and evaluated by models for cooperative self-assembly.
authors.affiliation: School of Chemical Engineering and Technology, Collaborative Innovation Center of Chemical Science and Chemical Engineering (Tianjin), Tianjin University, Tianjin, 300072, China.
authors.forename: Zhijian
authors.identifier: 0000-0002-1182-7340
authors.initials: Z
authors.lastname: Chen
authors.affiliation: School of Chemical Engineering and Technology, Collaborative Innovation Center of Chemical Science and Chemical Engineering (Tianjin), Tianjin University, Tianjin, 300072, China.
authors.forename: Yong
authors.initials: Y
authors.lastname: Liu
authors.affiliation: Institut für Organische Chemie, Center for Nanosystems Chemistry and Bavarian Polymer Institute (BPI), Universität Würzburg, Am Hubland, 97074, Würzburg, Germany.
authors.forename: Wolfgang
authors.initials: W
authors.lastname: Wagner
authors.affiliation: Institut für Organische Chemie, Center for Nanosystems Chemistry and Bavarian Polymer Institute (BPI), Universität Würzburg, Am Hubland, 97074, Würzburg, Germany.
authors.forename: Vladimir
authors.initials: V
authors.lastname: Stepanenko
authors.affiliation: School of Chemical Engineering and Technology, Collaborative Innovation Center of Chemical Science and Chemical Engineering (Tianjin), Tianjin University, Tianjin, 300072, China.
authors.forename: Xiangkui
authors.initials: X
authors.lastname: Ren
authors.affiliation: Institut für Organische Chemie, Center for Nanosystems Chemistry and Bavarian Polymer Institute (BPI), Universität Würzburg, Am Hubland, 97074, Würzburg, Germany.
authors.forename: Soichiro
authors.initials: S
authors.lastname: Ogi
authors.affiliation: Institut für Organische Chemie, Center for Nanosystems Chemistry and Bavarian Polymer Institute (BPI), Universität Würzburg, Am Hubland, 97074, Würzburg, Germany.
authors.forename: Frank
authors.identifier: 0000-0001-7245-0471
authors.initials: F
authors.lastname: Würthner
keywords: J-aggregates; functional dyes; optical properties; self-assembly; supramolecular chemistry