title: A Diradical Approach towards BODIPY-Based Dyes with Intense Near-Infrared Absorption around λ=1100 nm.
abstract: A diradical approach to obtain stable organic dyes with intense absorption around λ=1100 nm is reported. The para- and meta-quinodimethane-bridged BODIPY dimers BD-1 and BD-2 were synthesized and were found to have a small amount of diradical character. These molecules exhibited very intense absorption at λ=1088 nm (ɛ=6.65×10(5)  M(-1)  cm(-1) ) and 1136 nm (ɛ=6.44×10(5)  M(-1)  cm(-1) ), respectively, together with large two-photon-absorption cross-sections. Structural isomerization induced little variation in their diradical character but distinctive differences in their physical properties. Moreover, the compounds showed a selective fluorescence turn-on response in the presence of the hydroxyl radical but not with other reactive oxygen species.
authors.affiliation: Department of Chemistry, National University of Singapore, 117543, Singapore, Singapore.|Laboratory of Bioimaging Probe Development, Singapore Bioimaging Consortium, 138667, Singapore, Singapore.
authors.forename: Yong
authors.initials: Y
authors.lastname: Ni
authors.affiliation: Spectroscopy Laboratory for Functional π-Electronic Systems and Department of Chemistry, Yonsei University, Seoul, 120-749, Korea.
authors.forename: Sangsu
authors.initials: S
authors.lastname: Lee
authors.affiliation: Spectroscopy Laboratory for Functional π-Electronic Systems and Department of Chemistry, Yonsei University, Seoul, 120-749, Korea.
authors.forename: Minjung
authors.initials: M
authors.lastname: Son
authors.affiliation: Graduate School of Materials Science, Nara Institute of Science and Technology, 8916-5 Takayama-cho, Ikoma, 630-0192, Japan.
authors.forename: Naoki
authors.initials: N
authors.lastname: Aratani
authors.affiliation: Education Center for Global Leaders in Molecular Systems for Devices, Kyushu University, 744 Motooka, Nishi-ku, Fukuoka, 819-0395, Japan.
authors.forename: Masatoshi
authors.initials: M
authors.lastname: Ishida
authors.affiliation: Laboratory of Bioimaging Probe Development, Singapore Bioimaging Consortium, 138667, Singapore, Singapore.
authors.forename: Animesh
authors.initials: A
authors.lastname: Samanta
authors.affiliation: Graduate School of Materials Science, Nara Institute of Science and Technology, 8916-5 Takayama-cho, Ikoma, 630-0192, Japan.
authors.forename: Hiroko
authors.initials: H
authors.lastname: Yamada
authors.affiliation: Laboratory of Bioimaging Probe Development, Singapore Bioimaging Consortium, 138667, Singapore, Singapore.
authors.forename: Young-Tae
authors.initials: YT
authors.lastname: Chang
authors.affiliation: Education Center for Global Leaders in Molecular Systems for Devices, Kyushu University, 744 Motooka, Nishi-ku, Fukuoka, 819-0395, Japan.
authors.forename: Hiroyuki
authors.initials: H
authors.lastname: Furuta
authors.affiliation: Spectroscopy Laboratory for Functional π-Electronic Systems and Department of Chemistry, Yonsei University, Seoul, 120-749, Korea.
authors.forename: Dongho
authors.initials: D
authors.lastname: Kim
authors.affiliation: Department of Chemistry, National University of Singapore, 117543, Singapore, Singapore. chmwuj@nus.edu.sg.|Institute of Materials Research and Engineering, A*STAR, 2 Fusionopolis Way, Innovis, #08-03, 117602, Singapore, Singapore. chmwuj@nus.edu.sg.
authors.forename: Jishan
authors.initials: J
authors.lastname: Wu
keywords: BODIPY; dyes/pigments; fluorescence; radicals; reactive oxygen species