Polyalcohol ligand in CuII and FeIII cluster chemistry: Synthesis, structures and magnetic properties of {Cu12} and {Fe8} aggregates

Structurally unique {Cu12} and {Fe8} cluster complexes were synthesized using 2,2,6,6-tetrakis (hydroxymethyl)cyclohexanol (thcH5) ligand. The polyalcohol thcH5 ligand consists of a six membered ring in a chair confirmation and five pendant alcohol arms providing pentadentate-anchoring points for coordination chemistry. A wide range of reaction conditions was explored with transition metal ions in order to isolate large cluster complexes. Obtained {Cu12} and {Fe8} complexes exhibit unprecedented core topologies where thcH5 encapsulate and bridge between metal centers and mediate magnetic interactions via the superexchange pathways. Both complexes exhibit dominant intramolecular antiferromagnetic interactions leading to singlet spin ground state.