Efficient Dioxygen Activation and Capture by Triplet-Ground-State Pnictinidenes

Although dioxygen is indispensable for aerobic metabolism and cellular energy production, excessive exposure to oxygen can induce oxidative damage, thereby accelerating cellular dysfunction, promoting disease progression, and contributing to aging—a phenomenon commonly referred to as “oxygen toxicity.” To date, no experimental or theoretical studies have, to the best of our knowledge, examined the capture of triplet-ground-state O2 by stable triplet-ground-state molecular species. The present study therefore introduces a novel conceptual approach to the activation and capture of triplet O2. Thermodynamic and kinetic analyses reveal that, among the Group 15 pnictinidenes investigated, only [P-Rea]3 and [As-Rea]3 exhibit thermodynamically and kinetically favorable O2-capture processes. Activation strain analysis further demonstrates that the activation barrier is governed predominantly by the deformation energy required to distort the O2 molecule, together with the influence of the atomic radius of the Group 15 center.