An unprecedented Co^II cuboctahedron as the secondary building unit in a Co-based metal–organic framework

A cubic metal–organic framework with an unprecedented octanuclear secondary building unit (SBU) was isolated. The obtained SBU is composed of 8 Co^II ions at each vertex, 6 μ₄-OH groups at each face, and 12 cpt⁻ ligands framing the metal core. The cuboctahedra arrange in a ubt framework topology, eliciting a highly symmetrical MOF structure. Magnetic measurements as well as DFT calculations on this crystalline MOF reveal intramolecular antiferromagnetic coupling between Co^II ions in the octanuclear SBU.