A huge novel polyoxometalate-based cluster FePW exhibiting prominent electrocatalytic activity for the oxygen evolution reaction and third-order NLO properties.

Two novel POM-based huge clusters modified by conjugated organic ligands (DAPSC), {FePW} and {FeMoW}, have been successfully isolated. Compound 1 consists of a novel huge inorganic building block {FePW} and four organic groups DAPSC linked by ten iron ions and four sodium ions. The DAPSC ligands enhance the electric delocalization effects of polyoxoanions, leading to strengthening of the third-order nonlinear optical (NLO) responses of compounds 1-2. Additionally, the oxygen evolution reaction (OER) electrocatalytic activity and the magnetic properties of compound 1 have also been investigated.