I study and model the spin conversion in organic thermally activated delayed fluorescence (TADF) emitters with the aim of providing design guidelines to tailor these molecules for various purposes. My particular focus is on donor-acceptor substituted cyanoarenes for e.g. OLED applications and providing on-demand hyperpolarization. To better understand the underlying molecular mechanisms at play, including reverse intersystem crossing (RISC) from triplet to singlet states, I employ quantum chemical calculations as a basis for rate models, molecular dynamics in excited states, and molecular modeling.