Mechanochromic Luminescence from Crystals Consisting of Intermolecular Hydrogen‐Bonded Sheets. Issue 4 (22nd January 2020)

• Record Type: Journal Article
• Authors: Sagara, Yoshimitsu; Takahashi, Kiyonori; Nakamura, Takayoshi; Tamaoki, Nobuyuki
• Is Part Of: Chemistry, an Asian journal. Volume 15:Issue 4(2020)
• Page Start: 478
• Page End: 482
• Publication Date: 2020-01-22
• Subjects: crystals -- hydrogen bonds -- mechanochromic luminescence -- photoluminescence -- stimuli-responsive material; Chemistry -- Periodicals; 540.5
• DOI: 10.1002/asia.201901679
• Languages: English
• ISSNs: 1861-4728

Abstract

Abstract: Introduction of functional groups that can form intermolecular hydrogen bonds into highly‐emissive luminophores is a promising way to induce mechanochromic luminescence. Herein, we report that a 9, 10‐bis(phenylethynyl)anthracene derivative featuring two amide groups forms green‐emissive crystals based on two‐dimensional hydrogen‐bonded molecular sheets. Mechanical grinding changed the emission from green to yellow, owing to a transition from a crystalline to an amorphous phase. Infrared spectroscopy revealed that mechanical stimuli disrupted the linear hydrogen‐bonding formation. A thermal treatment recovered the original green photoluminescence. Abstract : A 9, 10‐bis(phenylethynyl)anthracene derivative featuring two amide groups forms green‐emissive crystals based on two‐dimensional intermolecular hydrogen‐bonded sheets. When mechanically ground, linear hydrogen bonding was partially disturbed, and the resultant excimer‐like species showed yellow emission. Thermal treatment recovered the initial crystalline state.