Modulation of piezochromic fluorescence behavior by subtle structural change

• Published in: Dyes and pigments Vol. 166; pp. 301 - 306
• Main Authors: Man, Tao, Xu, Nian-Sheng, Yu, Zhen-Hai, Huo, Yong, Yuan, Ye, Shi, Zi-Fa, Cao, Xiao-Ping, Wang, Lin, Zhang, Hao-Li
• Format: Journal Article
• Language: English
• Published: Elsevier Ltd 01.07.2019
• Subjects: Donor-acceptor structure; Intramolecular charge transfer; Modulation; Piezochromic material; Triphenylamine; Piezochromic material; Triphenylamine; Modulation; Intramolecular charge transfer; Donor-acceptor structure
• ISSN: 0143-7208; 1873-3743
• DOI: 10.1016/j.dyepig.2019.03.039

Two piezochromic molecules, (2Z,4E)-2-(4-(Diphenylamino)phenyl)-5-phenylpenta-2,4-dienenitrile (1a) and (2Z,4E)-2-(4-(acridin-10(9H)-yl)phenyl)-5-phenylpenta-2,4-dienenitrile (1b), were synthesized by using Knoevenagel and Buchwald-Hartwig cross-coupling reactions. Their piezochromic fluorescence behavior was tuned by subtle structural change. The system indicates typical intramolecular charge-transfer properties. The luminescence intensity of 1a decreased with increasing pressure with the redshift of the emission wavelength when the hydrostatic pressure in a diamond anvil cell (DAC) was applied on its crystal. However, the emission wavelength of 1b which has a methylene unit more than 1a had no obvious shift and the intensity increased gradually at the pressure range from 0.66 GPa to 5.72 GPa. [Display omitted] •Molecules 1a and 1b with donor-acceptor structure were synthesized.•Their piezochromic fluorescence behavior was modulated by a small difference in their structures.•The luminescence intensity of 1a decreased with increasing hydrostatic pressure with the redshift of the emission wavelength.•The emission wavelength of 1b had no obvious shift and the intensity increased gradually at the pressure 0.66 to 5.72 GPa.