Polymorphic crystals and their luminescence switching of triphenylacrylonitrile derivatives upon solvent vapour, mechanical, and thermal stimuli. Issue 13 (13th February 2015)

• Record Type: Journal Article
• Authors: Zhang, Yujian; Song, Qingbao; Wang, Kai; Mao, Wengang; Cao, Feng; Sun, Jingwei; Zhan, Lingling; Lv, Yaokang; Ma, Yuguang; Zou, Bo; Zhang, Cheng
• Is Part Of: Journal of materials chemistry. Volume 3:Issue 13(2015)
• Page Start: 3049
• Page End: 3054
• Publication Date: 2015-02-13
• Subjects: Materials -- Periodicals; Chemistry, Analytic -- Periodicals; Optical materials -- Research -- Periodicals; Electronics -- Materials -- Research -- Periodicals; 543.0284
• DOI: 10.1039/c4tc02826k
• Languages: English
• ISSNs: 2050-7526

Abstract

Abstract : The organic crystals BCrys, SCrys and YCrys with the blue, sky-blue, and yellow fluorescence, respectively exhibit the responsive fluorescence switching under grinding, heating and solvent vapour stimulation. Abstract : For piezo-, vapo-, and thermochromic materials, it remains a challenge to figure out the underlying reason for fluorescence color changes upon external stimulation and determine why only some fluorophores reveal emission switching. A novel triphenylacrylonitrile derivative (TPAN-MeO) with remarkably twisted conformations has been carefully prepared via the Suzuki coupling reaction. The fluorescence of TPAN-MeO in the aggregate state depends on the polymorphic forms: three crystalline forms BCrys, SCrys and YCrys exhibit bright blue, sky-blue and yellow emission, respectively; meanwhile the amorphous powders are also strongly fluorescent with green emission. The crystals BCrys and SCrys exhibit mechano- and piezochromism in that grinding and high pressure could alter the emission colour, respectively. In addition, the amorphous film exhibits vapo- and thermochromic behaviour in that organic vapour and heating could change the green colour into sky-blue. Interestingly, the solvent vapour and heating stimuli can trigger a crystal-to-crystal transformation between SCrys form and YCrys form.