Herein, we present a systematic investigation of dianionic clusters of the form of O©M5X52– (M = Li–Cs; X = F–I) aimed at identifying viable planar pentacoordinate oxygen (ppO) motifs. Across the complete combinatorial space examined, only the starlike D5h-O©Li5F52– cluster emerges as a true global minimum. Detailed bonding and magnetic response analyses reveal that this structure is stabilized predominantly by electrostatic interactions rather than by multicenter covalent bonding. These findings establish D5h-O©Li5F52– as the second confirmed ppO system and demonstrate that planar pentacoordinate oxygen can be realized under appropriate electrostatic confinement.
García-Argote et al. (Sat,) studied this question.