Metal-Centered Boron-Wheel Cluster of Y©B 11 2- with Rare D 11 h Symmetry.

Molecules with high point-group symmetry are interesting prototype species in the textbook. As transition metal-centered boron clusters tend to have highly symmetric structures to fulfill multicenter bonding and high stability, new boron clusters with rare point-group symmetry may be viable. Through in-depth scrutiny over the structures of experimentally already observed transition metal-centered boron-wheel complexes, geometric and electronic design principles are summarized, based on which we studied M©B11 k - ( M = Y, La; Zr, Hf; k = 1, 2) clusters and found that a Y©B11 2- boron-wheel complex has an unprecedented D 11 h point-group symmetry. The remarkable stability of the planar Y©B11 2- complex is illustrated via extensive global-minimum structural search as well as comprehensive chemical bonding analyses. Similar to other boron-wheel complexes, the Y©B11 2- complex is shown to possess σ and π double aromaticity, indeed following the electronic design principle previously summarized. This new compound is expected to be experimentally identified, which will extend the currently known largest possible planar molecular symmetry and enrich the metal-centered boron-wheel class.