Amplified Light-Induced\np<i>K</i><sub>a</sub> Modulation with Diarylethene Photoswitches

The reversible modulation of acidity using molecular\nphotoswitches\nenables the remote control of a variety of (bio)chemical processes\nwith light. Herein we investigated the structural features that allow\namplifying photoinduced p<i>K</i><sub>a</sub> variation\nin phenol-diarylethene conjugates, which toggle between low- and high-acidity\nstates by switching the conjugation between the ionizable moiety and\nelectron-withdrawing groups upon photoisomerization. By tuning the\nstructure of these conjugates, high p<i>K</i><sub>a</sub> modulation amplitudes were accomplished that surpass those previously\nreported.