An Optically and Thermally Switchable Electronic Structure Based on an Anthracene-BODIPY Conjugate

• Published in: Chemistry : a European journal Vol. 21; no. 13; pp. 4966 - 4974
• Main Authors: Aotake, Tatsuya, Suzuki, Mitsuharu, Tahara, Kazuaki, Kuzuhara, Daiki, Aratani, Naoki, Tamai, Naoto, Yamada , Hiroko
• Format: Journal Article
• Language: English
• Published: Weinheim WILEY-VCH Verlag 23.03.2015; WILEY‐VCH Verlag; Wiley; Wiley Subscription Services, Inc
• Subjects: Activation; Chemistry; Chemistry, Multidisciplinary; Data encryption; Data storage; Dyes; dyes/pigments; Electron transfer; Electronic structure; Excitation; Fluorescence; Heating; Hydrocarbons; molecular switches; photochemistry; Physical Sciences; Science & Technology; dyes/pigments; COMPLEX; DYES; FUSED BODIPYS; RED; electron transfer; fluorescence; photochemistry; PH; CHEMISTRY; RESPONSIVE FLUORESCENCE; EMISSION; PRECURSORS; molecular switches; BRIGHT
• ISSN: 0947-6539; 1521-3765
• DOI: 10.1002/chem.201406384

An optically and thermally responsive boron dipyrromethene (BODIPY) dye, namely, meso‐2‐(9,10‐dihydro‐9,10‐ethanoanthracene‐11,12‐dione) (DK)‐linked, bicyclo[2.2.2]octadiene (BCOD)‐fused BODIPY (BCOD‐DK), was synthesized. The weakly luminous structure of BCOD‐DK can be changed quantitatively to that of the strongly fluorescent BODIPY BCOD‐Ant by optical excitation at the DK unit, which induces double decarbonylation of the DK unit to give an anthracene unit. The solvent effect on the fluorescence properties of BCOD‐DK suggests that the dramatic change in fluorescence intensity is controlled by intramolecular electron transfer from the BODIPY moiety to the meso‐DK substituent. BCOD‐DK is converted to meso‐DK benzene‐fused BODIPY (Benzo‐DK) by heating at 220 °C with 64–70 nm redshift of absorption and fluorescence peaks without changing the fluorescence quantum yield of ΦF=0.08 in dichloromethane. Benzo‐DK can be converted to strongly fluorescent meso‐anthracene benzene‐fused BODIPY Benzo‐Ant by optical excitation. Thus, BCOD‐DK can show four different optical performances simply by irradiation and heating, and hence may be applicable for optical data storage and security data encryption. Four‐way switch: An optically and thermally switchable BODIPY dye was designed and synthesized (see figure). Separate photoexcitation for structure change and fluorescence monitoring was achieved by means of fluorescence quenching based on an intramolecular electron‐transfer mechanism. As the absorption characteristics can be switched by thermal activation, the construction of a completely irreversible multifluorescence switching system is possible.