Clear piezochromic behaviors of AIE-active organic powders under hydrostatic pressure. Issue 2 (23rd December 2015)

• Record Type: Journal Article
• Authors: Ouyang, Mi; Zhan, Lingling; Lv, Xiaojing; Cao, Feng; Li, Weijun; Zhang, Yujian; Wang, Kunyan; Zhang, Cheng
• Is Part Of: RSC advances. Volume 6:Issue 2(2016)
• Page Start: 1188
• Page End: 1193
• Publication Date: 2015-12-23
• Subjects: Chemistry -- Periodicals; 540.5
• DOI: 10.1039/c5ra21218a
• Languages: English
• ISSNs: 2046-2069

Abstract

Abstract : A diphenylacrylonitrile derivative exhibiting the aggregation induced emission and piezochromic behavior with clear wavelength changes under hydrostatic pressure. Abstract : A novel diphenylacrylonitrile derivative ( Z )-3-(4′-(diphenylamino)-[1, 1′-biphenyl]-4-yl)-2-(4-methoxyphenyl)-acrylonitrile (β-CN-TPA ) containing a twisted triphenylamine and diphenylacetonitrile was synthesized via Knoevenagel condensation and Suzuki coupling reactions. These molecules exhibited aggregation enhanced emission (AIE) effects. Interestingly, their mechano-fluorochromic properties were invisible upon grinding with a pestle. However, when hydrostatic pressure in a diamond anvil cell (DAC) was applied on the crystals ofβ-CN-TPA, the distinct piezochromic behaviors of the compound were observed. The fluorescence color changed from light green (530 nm) to red (665 nm) with a significant red-shift of 135 nm. The powder X-ray diffraction and high-pressure Raman studies indicated that the as-synthesized and ground samples had the same crystalline structures, while the compressed samples had an evident change in inter-molecular interactions. Comparative tests and theoretical analysis further confirmed that the distinct fluorescence behaviors of the desired dye during the different stress conditions were associated with the various inter-molecular interactions that existed with adjacent molecules.