Full-color tunable mechanofluorochromism and excitation-dependent emissions of single-arm extended tetraphenylethylenes

Abstract

We propose a new single-arm extension strategy on traditional tetraphenylethylene and successfully develop a new series of full-color (from ∼450 nm to ∼740 nm) tunable mechanofluorochromic materials. These materials exhibit efficient solid-state emission (quantum yield Φ_f > 10%) and high mechanofluorochromic contrast (wavelength shift from ∼50 nm to ∼100 nm). More importantly, we discover an unexpected excitation-dependent emission phenomenon of mechanofluorochromic materials and propose to utilize this new excitation-dependent emission behavior of materials to evaluate their mechanical-responsive performances more comprehensively. Finally, the unique feature of abundant emissions of mechanofluorochromic materials by changing the excitation light has shown application potential in dual channel anti-counterfeiting.