Photoluminescence behaviour of a stimuli responsive Schiff base: Aggregation induced emission and piezochromism. (January 2019)

• Record Type: Journal Article
• Authors: Yadav, Pranjalee; Singh, Ashish Kumar; Upadhyay, Chandan; Singh, Vinod P.
• Is Part Of: Dyes and pigments. Volume 160(2019)
• Page Start: 731
• Page End: 739
• Publication Date: 2019-01
• Subjects: Aggregation induced emission -- Piezochromism -- Fluorescence -- SEM & TEM -- X-ray crystallography; Dyes and dyeing -- Periodicals; Pigments -- Periodicals; 667.2
• DOI: 10.1016/j.dyepig.2018.08.065
• Languages: English
• ISSNs: 0143-7208

Abstract

Abstract: A naphthaldehyde based Schiff base, HMP has been synthesized by simple one-pot synthesis and characterized by IR, NMR and mass spectral techniques. HMP was non-emissive in acetonitrile, but its emission intensity was enhanced drastically (68 folds) upon addition of water, demonstrating typical aggregation induced emission (AIE) behaviour. Fluorescence quantum yield was increased drastically on aggregation from 0.3% (fw = 0%) to 8.1% (fw = 99%). Lifetime decay measurements were also performed in support of AIE property. Single crystal X-ray diffraction and DFT studies reveal that conformational transformation from benzenoid to quinonoid form induces restricted intramoleclar rotation (RIR) which contributes to AIE property. HMP was found to exhibit strong luminescence and piezochromism in solid state. Interestingly, dark yellow luminescence of crystalline HMP was changed to light green in response to grinding and a blue shift from 544 nm to 531 nm was observed. HMP exhibits good parent crystalline maintenance capability during grinding. Synthetic ease and reversible transformation of HMP are the key features to establish its application in pressjet printing and pressure sensing. Graphical abstract: A Schiff base (E)-1-(3-(((2-hydroxynaphthalen-1-yl)methylene)amino) phenyl) displaying remarkable aggregation induced emission and unique piezochromism has been synthesized and characterized. Image 1 Highlights: A simple and cost effective Schiff base has been synthesized and characterized. It offers a unique aggregation induced emission (AIE) and piezochromic behaviour. UV−Vis, fluorescence spectroscopy and SEM-TEM is used to study the AIE property. Piezochromic property is monitored by PXRD and solid state fluorescence. It is utilised in stress detection and security technologies.