1. Mechanofluorochromism of NIR-emitting dyes based on difluoroboron β-carbonyl cyclic ketonate complexes.
- Author
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Zhang, Fushuang, Zhai, Lu, Feng, Siwei, Mi, Wenhua, Sun, Jingbo, Sun, Meng, Zhao, Jinyu, and Lu, Ran
- Subjects
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NEAR infrared spectroscopy , *INFRARED spectroscopy , *SOLID state chemistry , *LUMINESCENCE , *PHOTON emission - Abstract
New difluoroboron β-carbonyl cyclic ketonate complexes CnB (n = 2, 16), in which carbazole was linked to difluoroboron β-diketonate directly, and DCnB (n = 2, 16), where two terminal carbazole units were bridged by vinyl groups to link to difluoroboron β-diketonate core, were synthesized. They exhibited reversible mechanofluorochromic (MFC) behavior under grinding/fuming or heating treatment. Particularly, the emission of DC2B and DC16B emerged in the range of 650–850 nm in the solid-state. They gave red and rose-red luminescence in the as-synthesized crystals and in the ground powders, respectively, during MFC processes. Such MFC materials emitting NIR (near-infrared) light were seldom reported. In addition, compared with C2B , C16B showed high-contrast mechanofluorochromism because the long alkyl chain might decrease the strength of π-π interactions in the as-synthesized crystals, leading to the emission appeared at the high-energy region (483 nm). The disassembling of parts of π-aggregates and the improvement of the molecular planarity led to red-shift of the emission (509 nm) upon grinding. [ABSTRACT FROM AUTHOR]
- Published
- 2018
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