A polyoxometalate-based single-molecule magnet with a mixed-valent {Mn(IV)2Mn(III)6Mn(II)4} core

Unusual assembly of lacunary heteropolymolybdates with cyanometalate fragment

Two new cyanide-bridged heteropolymolybdate complexes have been synthesized by a facile self-assembly process in aqueous solution, which demonstrates a successful tactic to incorporate the cyanometalate fragment into lacunary heteropolymolybdate. Magnetic investigation showed that complex 2 exhibits slow magnetic relaxation behavior.

Multinuclear cobalt(II)-containing heteropolytungstates: structure, magnetism, and electrochemistry

Interaction of the trilacunary Keggin polyanions [A-α-XW9O34](10-) (X = Si(IV), Ge(IV)) with Co(II) and phosphate ions in aqueous, basic media and under mild heating leads to the formation of the tetrameric, Co16-containing heteropolytungstates [{Co4(OH)3PO4}4(A-α-XW9O34)4](32-) (X = Si(IV), Ge(IV)). Both polyanions were characterized in the solid state by single-crystal X-ray diffraction, IR spectroscopy, and thermogravimetric and elemental analyses. Furthermore, the electrochemical and magnetic properties of these isostructural polyanions were investigated.

Unprecedented high-nuclear transition-metal-cluster-substituted heteropolyoxoniobates: synthesis by {V8 } ring insertion into the POM matrix and antitumor activities

Reactions of hexaniobate with vanadate in the presence of Ni(2+) , Zn(2+) , or Cu(2+) have furnished three high-nuclear vanadium cluster-substituted heteropolyoxoniobates (HPNs): {Ni(en)3 }5 H{V(V) Nb8 V(IV) 8 O44 }⋅9 H2 O (1), (H2 en)Na2 [{Zn(en)2 (Hen)}{Zn(en)2 (H2 O)}2 {PNb8 V(IV) 8 O44 }]⋅11 H2 O (2), and Na{Cu(en)2 }3 {[Cu(en)2 ]2 [PNb8 V(IV) 8 O44 ]}⋅11 H2 O (3) (en=1,2-diaminoethane). Their structures have been determined and characterized by single-crystal X-ray diffraction analysis, thermogravimetric analysis (TGA), and elemental analysis. Structural analysis has revealed that compounds 1-3 contain similar {V8 }-substituted [X(V) Nb8 V(IV) 8 O44 ](11-) (X=P, V) clusters, obtained by inserting a {V8 } ring into tetravacant HPN [XNb8 O36 ](27-) . To the best of our knowledge, compounds 1-3 represent the first high-nuclear vanadium cluster-substituted HPNs, and compound 1 is the largest vanadoniobate cluster yet obtained in HPN chemistry. Nickel and zinc cations have been introduced into HPNs for the first time, which might promise a more diverse set of structures in this family. Antitumor studies have indicated that compounds 1 and 2 exhibit high activity against human gastric cancer SGC-7901 cells, SC-1680 cells, and MG-63 cells.

Design and construction of a thermotropic liquid crystal material based on high-nuclear transition-metal cluster-containing polyoxometalates

DODA⁺ was used as a surfactant to react with polyoxoanion [Ni₉(OH)₃(H₂O)₆(HPO₄)₂(PW₉O₃₄)₃]¹⁶⁻, resulting in an organic–inorganic hybrid complex SEP-1, the first liquid crystal materials based on high-nuclear transition-metal cluster-substituted polyoxoanions.

Synthesis of a poly-pendant 1-D chain based on ‘trans-vanadium’ bicapped, Keggin-type vanadtungstate and its photocatalytic properties

A vanadtungstate cluster-based organic–inorganic hybrid material [NiL₄V^IVW^VI₁₀W^V₂O₄₀(V^IVO)₂] was synthesized, which not only serves as an active photocatalyst for the degradation of dye molecules, but also exhibits selective photocatalytic degradation of cationic dyes in aqueous solution.