The reversible mechanofluorochromic property of an asymmetric diketonate boron complex at room temperature

Abstract

A novel β-diketonate boron complex 2,2-Difluoro-6-methyl-4- (4-(1,2,2-triphenylvinyl)phenyl)-2H-1,3,2-dioxaborinin-1-ium-2-uide (BF2-TPEM) with mechanofluorochromic (MFC) property was synthesized through a typical Claisen condensation procedure. The new boron complex BF2-TPEM was characterized by 1H NMR, FT-IR, UV–vis, XRD, DSC and FL. The results show that the emission wavelength of BF2-TPEM complex is changed from 535 nm (yellow) to 550 nm (orange) under the grinding condition, and the grinding sample can be recovered from orange to yellow when it is heated. Moreover, it is also interesting to find that this material can achieve reversible mechanofluorochromic property at room temperature without the need for solvent fumigation or other stimulates, which is distinctly different from the MFC materials reported in the present literature. DSC measurements revealed that the reversible mechanofluorochromic property of BF2-TPEM was assumed to be related to the spontaneously crystallization process. This new MFC material with reversible mechanofluorochromic property at room temperature has a great potential for application in the field of information security and sensors.