Syntheses, Structures And Properties Of Rare-substituted Heptamolybdate Derivatives

The paper select ammoinum heptamolybdate and lanthanide as material, ten novel RE-substitutedisopolyoxoheptamolybdates derivatives were successfully synthesized under the conventional aqueousmethod and characterized by X-ray single crystal diffraction, spectroscopic properties （IR, UV, XPS andXRD）, thermal properties （TG） and fluorescence properties.1. Five two-dimensional lanthanide–containing peroxoisopolyoxomolybdates derivativesNa₂（NH₄）₃[H₃{Ln（H₂O）₅}₂Ln₄（H₂O）₁₆（MoO₄）{Mo₇O₂₂（O₂）₂}₄]·nH₂O [n=24; Ln=Ce^III（1）,Pr^III（2）, Sm^III（4）, Eu^III（5）; n=25; Ln=Nd^III（3）] have been successfully isolated. The structural analyses indicate that1⁵are isostructural. They are constructed from [Ln₄（H₂O）₁₆（MoO₄）{Mo₇O₂₂（O₂）₂}₄]^14-which is linked byLn³⁺cation to form two-dimensional frame structures. The photoluminescence measures reveal that4and5show obvious luminescence signal.2. An novel one-dimensional lanthanide–containing peroxoisopolyoxomolybdates derivativesNa₄（NH₄）₃[H₄{La（H₂O）₅}La₄（MoO₄）（H₂O）₁₆{Mo₇O₂₂（O₂）₂}₄]·17H₂O have been successfully obtained. Thepolyanion is same to1⁵and linked by La3+cation to form one-dimensional chain structures.3. Four novel lanthanide–containing isopolyoxomolybdates derivativesNa₄（NH₄）₃[H₄{Ln（H₂O）₅}Ln₄（H₂O）₁₆（MoO₄）(Mo₇O₂₄)₄]·13H₂O[Ln=Pr^III（7）, Sm^III（8）]，K₃（NH₄）₃[H_6.5{Ln_0.5（H₂O）₇}Ln₄（H₂O）₁₆（MoO₄）(Mo₇O₂₄)₄]·12H₂O[Ln=Nd^III（9）, Eu^III（10）] have been successfullyisolated. They have the same polyanion [Ln₄（H₂O）₁₆（MoO₄）(Mo₇O₂₄)₄]^14-. The photoluminescencemeasures reveal that8and10show obvious luminescence signal.