The synthesis, crystallographic analysis and full characterization of the Cu(I) complex-functionalized Anderson polyoxomolybdate anions (ⁿBu₄N)[MMo₆O₁₈((OCH₂)₃CNCH(C₄₇H₃₇N₂P₂OCu)₂)] (M = Mn³⁺, Fe³⁺, Co³⁺) is reported. For the first time, direct crystallographic evidence for the covalent attachment of a photoactive metal complex to an organo-functionalized polyoxometalate is obtained. Initial electrochemical and photochemical studies report fundamental properties and solution stability of the compounds.