The reactivity of Co (II) toward oxygen is rooted in its electronic configuration and the associated orbital interactions. Co (II) typically possesses a d 7 electronic configuration, where its partially filled t2g and Eg orbitals provide a versatile platform for engaging with oxygen molecules . The high-spin state of Co (II) often features unpaired electrons, which facilitate a strong affinity for paramagnetic oxygen due to spin-pairing interactions . This capability is further amplified by the ability of Co (II) to transition between oxidation states, such as Co (III), during oxygen activation processes . The d-orbitals of Co (II) engage in π-back donation, stabilizing the bound oxygen molecule and enabling the cleavage of the O=O bond in catalytic applications like oxygen reduction and oxygen evolution reactions. This interplay of orbital symmetry and redox flexibility underpins the high reactivity of Co (II) with molecular oxygen.