A change in luminescence upon grinding of tBuTPA-BQ and TPPA-BQ prompted us to investigate the piezochromic properties of these compounds in detail. Both as-prepared and sublimed samples of MeTPA-BQ emit in the near-IR region at lPL of 735 nm. Upon grinding, there is only a modest red-shifting of the emission to 745 nm (Figure ). The as-prepared sample of tBuTPA-BQ emits at λPL = 715 nm (FWHM = 152 nm); however, the emission of the sublimed form is significantly blue-shifted and not as broad (λPL = 622 nm; FWHM = 82 nm) (Figure ), having a FPL of 10.8% and a tPL of 4 ns. Similar to that observed for MeTPA-BQ, the as-prepared sample of tBuTPA-BQ showed little piezochromism. Surprisingly, the application of mechanical pressure on the sublimed sample results in a significant change in its photophysics, where after grinding, the sample now emits at lPL of 720 nm (FWHM = 148 nm) and has a FPL of only 0.8% and a tPL of 1.7 ns (Figure ). Upon exposure to solvent fumes (hexane, Et2O, DCM, THF and EtOAc), the photophysics of tBuTPA-BQ do not revert to the as-prepared form (Figure ).