Achieving tunable dual-emissive and high-contrast mechanochromic materials by manipulating steric hindrance effects

摘要

A series of unsymmetrical diphenylketone derivatives with tunable dual-emissive and high-contrast mechanochromic properties are reported. These compounds show dual-emissive bands in both solution and the solid state, by combining traditional fluorescence (ca. 426-459 nm) and intermolecular thermally activated delayed fluorescence (ca. 565-575 nm). Various photophysical studies and single crystal analyses are undertaken to demonstrate the dual-emissive mechanism and effect of bulky groups on regulating dual emissions. In addition, OPNa, OPAn and OPPy show white-light emission with the CIEx,y coordinates (0.32, 0.33), (0.33, 0.32) and (0.30, 0.34) in the solid state and high-contrast mechanochromism from blue and cold white to yellow emission. These studies present an ingenious design strategy for the development of high-performance multifunctional and single-component white-light-emitting materials.