A new family of polyoxometalate compounds built up of Preyssler anions and trivalent lanthanide cations

Four new polyoxometalate compounds built on Preyssler anions and trivalent lanthanide cations, Na₂[{Ce(H₂O)₈}₄{Na(H₂O)P₅W₃₀O₁₁₀}] · 12H₂O (1), H₄Na₄[Nd₂(H₂O)₁₄{Na(H₂O)P₅W₃₀O₁₁₀}] · 22H₂O (2), K₂Na[Eu₃(H₂O)₁₄(HNA)₃{Eu(H₂O)P₅W₃₀O₁₁₀}] · 3H₂O (3 NA = nicotinic acid) and H₂[Ce₄(H₂O)₁₆(HNA)₆{Na(H₂O)P₅W₃₀O₁₁₀}] · 12H₂O (4) have been synthesized and characterized by elemental analysis, IR, TG and single crystal X-ray diffraction. Compound 1 exhibits a tetrasupporting polyoxometalate cluster structure where four {Ce(H₂O)₈}³⁺ fragments are supported on the [Na(H₂O)P₅W₃₀O₁₁₀]¹⁴⁻ cluster. Compound 2 shows a one-dimensional chain structure built from [Na(H₂O)P₅W₃₀O₁₁₀]¹⁴⁻ clusters linked by Nd³⁺ cations. Compound 3 displays a one-dimensional chain structure constructed of [Eu(H₂O)P₅W₃₀O₁₁₀]¹²⁻ clusters bridged by Eu³⁺ cations. Compound 4 has a 2D network formed by 1D chains and {Ce₂(H₂O)₆(HNA)₆}⁶⁺ linkers. Compounds 2-4 represent the first extended structures based on Preyssler anions. In addition, the fluorescent activity of compound 3 is reported.