Multistate reactivity of weak-field clusters at ambient temperatures.

Ambient-temperature reactivity in biological and industrially relevant reactions is typically attributed from the ground state as a sufficiently large energy gap between ground and excited states of reactants renders the thermal Boltzmann population of excited states as a minor perturbation. However, interactions between locally high-spin centers in polynuclear clusters can afford low-lying excited states with appreciable populations at ambient temperature and provide alternate reaction pathways. Consequently, a mechanistic understanding of the reactivity of such clusters presents challenges. In this perspective, we consider advances towards dissecting the effects of such low-lying states on reactivity.