An unprecedented CoII 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 mu(4)-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 anti-ferromagnetic coupling between Co-II ions in the octanuclear SBU.