Novel halogen-bonded co-crystals and their unique luminescence property during 10 GPa compression-decompression cycle. (April 2020)

• Record Type: Journal Article
• Authors: Li, Aisen; He, Jian; Wang, Jing; Bi, Changjiang; Xu, Shuping; Xu, Weiqing; Cui, Haining
• Is Part Of: Dyes and pigments. Volume 175(2020)
• Publication Date: 2020-04
• Subjects: Co-crystal -- High pressure -- Intermolecular charge transfer -- Enhanced fluorescence -- Irreversibility; Dyes and dyeing -- Periodicals; Pigments -- Periodicals; 667.2
• DOI: 10.1016/j.dyepig.2019.108116
• Languages: English
• ISSNs: 0143-7208

Abstract

Abstract: A novel halogen bond-based co-crystal, 4, 4′-trimethylenedipyridine/1, 4-diiodotetrafluorobenzene (TMDP-DITFB), was achieved, which displays distinct piezochromic luminescence from none to a broad emission band (500–700 nm) assigned to the new intermolecular charge transfer (CT) state caused by the enhanced I⋯N interactions between TMDP and DITFB. Interestingly, once the pressure was released to the ambient condition, the emission of TMDP-DITFB could not be restored to initial state, but exhibited a new red maximum emission band at 668 nm, which is different from most piezochromic materials. Almost no change for the TMDP crystal was observed during the compression-decompression cycle. Comparative analysis between TMDP and TMDP-DITFB demonstrates that irreversible changes in fluorescence are highly related to intermolecular interactions between TMDP and co-formers modulated by pressure. Pressure-induced enhanced and irreversible emission of organic materials is rarely reported. This work enables deeper understanding on the structure-property relationship and put forward a new strategy to realize new properties of materials. Graphical abstract: Image 1 Highlights: A TMDP-DITFB co-crystal is obtained via intermolecular I⋯N interactions. Intermolecular charge transfer brings TMDP-DITFB remarkable pressure-induced emission enhancement. TMDP-DITFB exhibits irreversible emission during compression-decompression process.