Dual-state emission and mechanofluorochromic properties of coumarin derivatives containing α-cyanostilbene. (April 2023)

• Record Type: Journal Article
• Authors: Zhang, Yuyang; Hu, Zhenzhen; Xu, Jiale; Song, Zhongming; Mao, Yueyuan; Tang, Jing; Guo, Jiahao; Wang, Xuchun
• Is Part Of: Dyes and pigments. Volume 212(2023)
• Publication Date: 2023-04
• Subjects: Coumarin derivatives -- α-cyanostilbene -- Fluorescent materials -- Dual-state emission -- Mechanofluorochromic property -- Structure-property relationship; Dyes and dyeing -- Periodicals; Pigments -- Periodicals; 667.2
• DOI: 10.1016/j.dyepig.2023.111145
• Languages: English
• ISSNs: 0143-7208

Abstract

Abstract: Four novel coumarin derivatives (CM-H, CM-F, CM-CH 3 and CM-CF 3 ) functionalized by α-cyanostilbene unit were designed and synthesized. The molecular spatial structure and photophysical performances were systematically studied and discussed. The fluorescent spectra indicate that these coumarin derivatives display dual-state emission (DSE) characteristic. In dilute organic solutions, strong fluorescent emissions originated from intramolecular charge transfer (ICT) process, and in aggregated states, the bright fluorescent emissions are attributed to the collective effects of restriction of intramolecular motions and J -aggregation stacking. Meanwhile, these coumarin derivatives all exhibited mechanofluorochromic (MFC) property, in particular, compound CM-CF 3 exhibit the reversible conversion between yellow and red emission. The XRD and SEM experimental results confirm that the MFC mechanism is based on the conversion of degree of crystallinity. Our study provides a reasonable approach for designing DSE materials with the MFC property. Highlights: Four novel coumarin derivatives functionalized by α-cyanostilbene unit were designed and synthesized. These coumarin derivatives displayed dual-state emission characteristic. These coumarin derivatives all exhibited mechanofluorochromic property.