Mechanofluorochromism of pyrenyl acrylates with different substitutional position and steric hindrance

Solid-state emission color change upon mechanical stimuli, known as mechanofluorochromism (MFC), is reported for pyrenyl acrylates. The C-1- and C-4-alkenylated pyrenes ((E)-Ethyl-3-(Pyren-1-yl)acrylate (E)-Ethyl-3-(Pyren-4-yl)acrylate, respectively) exhibited distinct MFC behaviors (hypsochromic bathochromic shifts). introduction of bulky tert-butyl groups in 2,7-position ((E)-Ethyl-3-(2,7-Di-tert-butylpyren-4-yl)acrylate) also induced the shifted overlapping pyrene moiety pristine form suppressed thermal back reaction ground form. These characteristic pyrene-derived acrylates are discussed on basis spectra decay times forms.