Self-Assembled Monolayers of Diazocine Photoswitches: Inverted Isomer Stability and Surface Wettability

Diazocine has recently caught attention as a unique photoswitch, providing an inverse photoisomerization in comparison to azobenzene since <i>Z</i>-diazocine is thermodynamically more stable than <i>E</i>-diazocine. In this article, we present the synthesis of an organosilane-functionalized diazocine and the successful formation of self-assembled monolayers of diazocine on quartz glass and silicon oxide substrates. Reversible photoisomerization and photoresponsive surface wettability were observed upon alternating exposure of the monolayers to UV and green light. Remarkably, both the inverse isomer stability and the inverse effect of UV irradiation on the surface wettability of diazocine and azobenzene were preserved in the molecular monolayer.