Rhodanine-Based Chromophores: Fast Access to Capable Photoswitches and Application in Light-Induced Apoptosis

Abstract

Molecular photoswitches are highly desirable in all chemistry-related areas of research. They provide effective outside control over geometric and electronic changes at the nanoscale using an easy to control and waste-free stimulus. However, simple and effective access to such molecular tools is typically not granted and elaborate syntheses and substitution schemes are needed in order to obtain efficient photoswitching properties. Here we present a series of rhodanine-based photoswitches that are prepared in one simple synthetic step without requiring elaborate purification. Photoswitching is induced by UV and visible light in both switching directions and thermal stabilities of the metastable states are high. An additional benefit is the hydrogen bonding capacity of the rhodanine fragment, which enables applications in supramolecular or medicinal chemistry. We further show that the known rhodanine-based inhibitor SMI-16a is a photoswitchable apoptosis inducer. The activity of SMI-16a can be switched ON or OFF by reversible photoisomerization between the inactive E and the active Z isomer. Rhodanine-based photoswitches therefore represent an easy to access and highly valuable molecular toolbox for implementing light responsiveness to functional molecular systems.

Path-independent all-visible orthogonal photoswitching for applications in multi-photochromic polymers and molecular computing

“…In this work we establish an all-visible, all-photon, path-independent orthogonal photoswitching system enabling to enrich each of the four possible states with very high yields (Figure 1). To this end we use a combination of two indigoid photoswitch types 48,49 disseminated only recently by our group, a rhodanine derivative 1 50 and perianthracenethioindigo (PAT) 2. 51 The resulting four switching states of 1 and 2 are significantly distinct in their spectral signatures and resulting color, which established a four-state photochromic behavior.…”