Mechanically induced single-molecule white-light emission of excited-state intramolecular proton transfer (ESIPT) materials. Issue 5 (10th March 2021)

• Record Type: Journal Article
• Authors: Huang, Quan; Guo, Qiang; Lan, Jingbo; Su, Rongchuan; Ran, You; Yang, Yudong; Bin, Zhengyang; You, Jingsong
• Is Part Of: Materials horizons. Volume 8:Issue 5(2021)
• Page Start: 1499
• Page End: 1508
• Publication Date: 2021-03-10
• Subjects: Materials -- Research -- Periodicals; 543.0284
• DOI: 10.1039/d0mh02032j
• Languages: English
• ISSNs: 2051-6347

Abstract

Abstract : Disclosed herein is the first example of a mechanically induced single-molecule white-light emission of ESIPT materials. Mechanical grinding transforms intermolecular packing motifs, enabling emission color switching from yellowish green to white. Abstract : Described herein is the first example of mechanically induced single-molecule white-light emission based on excited-state intramolecular proton transfer (ESIPT) materials. The mechanism of mechanochromism is clearly disclosed by powder and single crystal X-ray diffraction (XRD) data, infrared spectroscopy, and fluorescence up-conversion measurement, etc. 2-(2′-Hydroxyphenyl)oxazole (6b) with a herringbone packing motif exhibits a predominant keto-form emission, giving off yellowish-green fluorescence. Mechanical grinding transforms the herringbone packing motif into a brickwork packing motif, decreases the intermolecular distances, which results in an enhanced intermolecular charge-transfer interaction, and therefore changes the ESIPT dynamics, leading to an enhanced enol-form emission and white fluorescence. Herringbone-packing 6b is thermodynamically more stable than brickwork-packing 6b. Thus, the latter can convert to the former by solvent fuming or thermal annealing.