Two organic-inorganic hybrid 3D {P₅W₃₀}-based heteropolyoxotungstates with transition-metal/ln-carboxylate-Ln connectors

Two unique organic-inorganic hybrid polyoxometalates constructed from Preyssler-type [Na(H₂O)P₅W₃₀O ₁₁₀]^14- ({P₅W₃₀}) subunits and TM/Ln-carboxylate-Ln connectors (TM=transition metal, Ln=lanthanide), KNa ₇[{Sm₆Mn(μ-H₂O)₂(OCH ₂COO)₇(H₂O)₁₈}{Na(H ₂O)P₅W₃₀O₁₁₀}]×22 H ₂O (1) and K₄[{Sm₄Cu₂(gly) ₂(ox)(H₂O)₂₄}{NaP₅W ₃₀O₁₁₀}]Cl₂×25 H₂O (2; gly=glycine, ox=oxalate) have been hydrothermally synthesized and characterized by elemental analyses, IR spectra, UV/Vis-NIR spectra, thermogravimetric analyses, power X-ray diffraction, and single-crystal X-ray diffraction. Compound 1 displays one interesting 3D framework built by three types of subunits, {P₅W₃₀}, [Sm₂Mn(μ-H ₂O)₂(OCH₂COO)₂(H₂O) ₅]⁴⁺, and [Sm₄(OCH₂COO)₅ (H₂O)₁₃]²⁺, whereas 2 also manifests the other intriguing 3D architecture created by three types of subunits, {P ₅W₃₀}, [SmCu(gly)(H₂O)₈] ⁴⁺, and [Sm₂(ox)(H₂O)₈] ⁴⁺. To our knowledge, 1 and 2 are the first 3D frameworks that contain {P₅W₃₀} units and TM/Ln-carboxylate-Ln connectors. The fluorescent properties of 1 and 2 have been investigated. Now in 3D! The first {P₅W₃₀}-based transition-metal (TM)-Ln heterometallic clusters exhibit unprecedented 3D frameworks that consist of {P₅W₃₀} subunits and TM/Ln-carboxylate-Ln connectors (see figure).