Position- and region-isomerized derivatives of a V-shaped fluorophore: the unique solution-state dual emission and the unusual force-induced solid-state turn-on emission
the ortho- and meta-isomers in both solution and solid states. The rare turn-on solid-stateemission of such isomers under force stimuli is caused by the enhanced π-conjugation effect on excited molecules, which are released from broken lattices to possess more planarized geometries. Moreover, the red shifts of emission wavelengths before and after force application are remarkably reduced from the parent