Energetics for Hydrogen Atom Transfer by Ketyl Radicals: Is Thermodynamics on Your Side?

ABSTRACT Ketyl radicals play a key role in various reaction mechanisms, where their ability to donate hydrogen atoms governs numerous processes, ranging from photoredox catalysis to biological mechanisms and the synthesis of metal nanoparticles. Despite their significance, the thermochemical parameters that dictate their behavior remain poorly understood, leading to many inconsistencies in the literature. This minireview aims to provide a comprehensive perspective, addressing these inconsistencies that only emerge when comparing a family of reactions where available data challenge our understanding of chemical reactivity. The tables presented here, in combination with other resources, offer a robust and consistent reactivity paradigm that aligns well with the experimental reactivity of ketyl radicals.