Dual-mode photoswitching of luminescence

Abstract
The fluorescence and chirality of photoswitchable inherently dissymmetric alkenes cis1 and trans-2-nitro-7-dimethylamino-9-(2′,3′-dihydro-1′H-naphtho[2,1-b]thiopyran-1′-ylidene)-9H-thioxanthene 2 are reversibly modulated by irradiation whereas photoresponsive effects and emission are regulated by reversible protonation.