Cyano-substituted oligo(p-phenylene vinylene) derivatives can display piezochromic fluorescence. This rare and desirable effect is achieved by balancing pi-pi and aliphatic interactions in these molecules through the variation of electron density in the central ring and the length of peripheral aliphatic tails. This leads to fluorophores which can adopt different supramolecular structures and as a result can change their solid-state emission characteristics upon compression.