The paper presents research on chiroptical molecular switches, developed by Ben L. Feringa, Nina P. M. Huck, and Anne Marie Schoevaars. These switches utilize chiral photoresponsive molecules to control optical properties, enabling information storage and retrieval. The switches operate based on the interconversion of two chiral forms of helically shaped molecules, P and M, which exhibit distinct optical properties. The switching process is triggered by light, and the photostationary state is determined by the wavelength of the light used. The optical rotation at wavelengths remote from the switching wavelengths allows for non-destructive read-out. The molecular design of the switches involves sterically-overcrowded unsymmetrical thioxanthenes, which can undergo photochemical cis-trans isomerization, resulting in reversal of helicity. The racemization barriers can be tuned by modifying the bridging unit, and the thermal and photochemical stability can be enhanced by introducing a bridging sulfur atom. The switching unit can be tethered to polymers or other functional units via appropriate spacers. The research also explores highly stereoselective optical molecular switching, demonstrating the ability to control the photostationary states of chiral molecules through light. The switches can be used for writing, reading, and erasing information, with the potential for an EDRAW (Erasable Direct Read After Write) process. The switches also exhibit gated response, where the switching process can be controlled by external stimuli, such as protonation of donor functionalities. The study further investigates the application of these switches in liquid crystalline phases, demonstrating the ability to induce cholesteric phases through the addition of chiral photoresponsive molecules. The switches can be used to modulate the pitch of the cholesteric phase, and the macroscopic assembly can be controlled by the ratio of helices of the dopant. The results suggest that chiroptical switching can be applied in other films and supramolecular assemblies, paving the way for photocontrol in various applications. The research highlights the potential of chiroptical molecular switches in the development of new materials and technologies.The paper presents research on chiroptical molecular switches, developed by Ben L. Feringa, Nina P. M. Huck, and Anne Marie Schoevaars. These switches utilize chiral photoresponsive molecules to control optical properties, enabling information storage and retrieval. The switches operate based on the interconversion of two chiral forms of helically shaped molecules, P and M, which exhibit distinct optical properties. The switching process is triggered by light, and the photostationary state is determined by the wavelength of the light used. The optical rotation at wavelengths remote from the switching wavelengths allows for non-destructive read-out. The molecular design of the switches involves sterically-overcrowded unsymmetrical thioxanthenes, which can undergo photochemical cis-trans isomerization, resulting in reversal of helicity. The racemization barriers can be tuned by modifying the bridging unit, and the thermal and photochemical stability can be enhanced by introducing a bridging sulfur atom. The switching unit can be tethered to polymers or other functional units via appropriate spacers. The research also explores highly stereoselective optical molecular switching, demonstrating the ability to control the photostationary states of chiral molecules through light. The switches can be used for writing, reading, and erasing information, with the potential for an EDRAW (Erasable Direct Read After Write) process. The switches also exhibit gated response, where the switching process can be controlled by external stimuli, such as protonation of donor functionalities. The study further investigates the application of these switches in liquid crystalline phases, demonstrating the ability to induce cholesteric phases through the addition of chiral photoresponsive molecules. The switches can be used to modulate the pitch of the cholesteric phase, and the macroscopic assembly can be controlled by the ratio of helices of the dopant. The results suggest that chiroptical switching can be applied in other films and supramolecular assemblies, paving the way for photocontrol in various applications. The research highlights the potential of chiroptical molecular switches in the development of new materials and technologies.