In particular, Yoon's group aims to leverage the ability of visible light–absorbing transition metal complexes to catalyze synthetic reactions. They investigate various mechanisms of photocatalytic activation, which differ from complex to complex depending on reactivity patterns of intermediates and their ability to be activated by sources of white light, including sunlight. Traditionally, chemists have used high-energy UV light to activate simple organic molecules, but Yoon's group focuses instead on expanding the application of visible light sources to synthesize increasingly complex target molecules. By providing strategies for activation of organic substrates that do not require specialized high-pressure UV photolysis apparatuses, these procedures are rendered more environmentally-friendly and widely available to synthetic and organic chemists.
