Excited state dynamics of some nonsteroidal anti-inflammatory drugs: A surface-hopping investigation

Here we present a computational investigation of the excited state dynamics of 5 different active medical substances (aspirin, ibuprofen, carprofen, suprofen, indomethacin) which belong to the family of nonsteroidal anti-inflammatory drugs (NSAIDs). The nonadiabatic dynamics simulations were performed using the surface hopping method, with electronic energies and couplings evaluated on the fly in a semiempirical framework. For aspirin, the solvent decay dynamics was also considered by inserting it in a cluster of water molecules, following a QM/MM scheme. A quite diverse behavior was observed for the systems considered, going from fast deactivation to the S 0 (aspirin and ibuprofen), to ultrafast intersystem crossing to the triplet manifold (carprofen and suprofen), or to the generation of long lived S 1 states (indomethacin). To our knowledge, this is the first computational study of the photodynamics of these NSAIDs.