Thermal half-lives of azobenzene derivatives: virtual screening based on intersystem crossing using a machine learning potential
This work addresses the need for efficient prediction of photoswitch properties in photopharmacology, though it is incremental as it builds on existing evidence about intersystem crossing mechanisms.
The researchers tackled the problem of predicting thermal half-lives for azobenzene derivatives, which are crucial for light-activated drugs, by developing a computational tool using a machine learning potential; they predicted half-lives for 19,000 derivatives and provided open-source data and software.
Molecular photoswitches are the foundation of light-activated drugs. A key photoswitch is azobenzene, which exhibits trans-cis isomerism in response to light. The thermal half-life of the cis isomer is of crucial importance, since it controls the duration of the light-induced biological effect. Here we introduce a computational tool for predicting the thermal half-lives of azobenzene derivatives. Our automated approach uses a fast and accurate machine learning potential trained on quantum chemistry data. Building on well-established earlier evidence, we argue that thermal isomerization proceeds through rotation mediated by intersystem crossing, and incorporate this mechanism into our automated workflow. We use our approach to predict the thermal half-lives of 19,000 azobenzene derivatives. We explore trends and tradeoffs between barriers and absorption wavelengths, and open-source our data and software to accelerate research in photopharmacology.