An organophosphate 3d-4f heterometallic polyoxoniobate nanowire

Four different structural compositions of organophosphate, 3d transition metal, 4f lanthanide and polyoxoniobate (PONb) are unified in a system for the first time to form a new type of organophosphate 3d-4f heterometallic inorganic-organic hybrid PONb nanowire. Interesting magnetic anisotropy and slow magnetic relaxation are found in the PONb nanowire.

3d-4f Heterometallic cluster incorporated polyoxoniobates with magnetic properties

A series of 3d-4f heterometallic cluster incorporated polyoxoniobates (PONbs) with different magnetic properties were first made and characterized. This work not only provides a promising strategy to make new heterometallic cluster incorporated PONbs but also demonstrates an ideal model to probe how transition-metal ions influence the magnetic property of PONbs.

A new family of decanuclear Ln7Cr3 clusters exhibiting a magnetocaloric effect

Two dimeric Ln–Cr clusters with formula {Ln(H₂O)₈[Ln₆Cr₃(L)₆(CH₃COO)₆(μ₃-OH)₁₂(H₂O)₁₂]}·(ClO₄)₆·xH₂O (Ln = Gd, x = 35 for 1 and Ln = Dy, x = 45 for 2, HL = 2-pyrazinecarboxylic acid) were obtained by a ligand-controlled hydrolytic method with a mixed ligand system (2-pyrazinecarboxylic acid and acetate). Single crystal structure analysis showed that two trigonal bipyramids of [Gd₃Cr₂(μ₃-OH)₆]⁹⁺ worked as building blocks in constructing the metal-oxo cluster core of [Gd₆Cr₃(μ₃-OH)₁₂]¹⁵⁺ by sharing a common top – a Cr³⁺ ion. Additionally, compound 1 forms a three-dimensional framework with a one-dimensional nanopore channel along the a-axis through a hydrogen-bond interaction between the cationic cluster core and the free mononuclear cation [Gd(H₂O)₈]³⁺ and the π-bond interactions of the pyrazine groups on the two cationic cluster cores. Magnetic calculations indicated a weak ferromagnetic coupling interaction for Gd⋯Gd and Gd⋯Cr in compound 1, with its magnetic entropy change (−ΔS_m) reaching 21.1 J kg⁻¹ K⁻¹ at 5 K, 7 T, while compound 2 displayed an obvious frequency-dependency at H_dc = 2000 Oe.

Two decanuclear Ln–Cr clusters Ln₇Cr₃ were obtained, which formed a three-dimensional framework with one-dimensional nanopore channel through hydrogen-bond and π-bond interactions. Gd₇Cr₃ had a magnetic entropy change of 21.1 J kg⁻¹ K⁻¹ at 5 K, 7 T.

Two Ni/Co-substituted sandwich-type germanomolybdates based on an unprecedented trivacant polyanion [α-GeMo10O36]8

Two Ni/Co-substituted sandwich-type germanomolybdates, {[M₃(NH₂-trz)₆(H₂O)₆][M₄(H₂O)₂(HGeMo₁₀O₃₆)₂]}·nH₂O (M = Ni²⁺ (1) and Co²⁺ (2), n = 10 (1) or 11 (2), NH₂-trz = 4-amino-1,2,4-triazole), have been obtained under hydrothermal conditions. 1 and 2 represent the first trivacant Keggin germanomolybdates involving unprecedented [α-GeMo₁₀O₃₆]^8- fragments and {M₃O₄} quasi-cubane building units. Both of them exhibit electrocatalytic behaviours for H₂O₂ reduction and photocatalytic properties for CO₂ conversion.

Two organic–inorganic hybrid polyoxotungstogermanates containing organic ligand chelated Fe–Dy heterometallic clusters and frequency dependent magnetic properties

Two organic–inorganic hybrid polyoxotungstogermanates are constructed from organic ligand chelated Fe–Dy heterometallic clusters and [B-α-GeW₉O₃₄]¹⁰⁻ units with frequency dependent magnetic properties.

Incorporating polyoxometalates and organic ligands to pursue 3d–4f heterometallic clusters: a series of {Cr4Ln4} clusters stabilized by phthalic acid and [SiW12O40]4−

By introduction of trilacunary Keggin-type polyoxometalate to the hydrothermal reaction system of Cr³⁺, Ln³⁺ and phthalic acid, a series of novel {Cr₄Ln₄} heterometallic clusters with the formula Cs₂[Cr₄Ln₄(μ₄-O)₄(μ₃-O)₄(C₈H₄O₄)₄(H₂O)₁₂](H₃SiW₁₂O₄₀)Cl·23H₂O (1-Ln, Ln = Ce, Pr, Nd) and [Cr₄Ln₄(μ₄-O)₄(μ₃-O)₄(C₈H₄O₄)₄(H₂O)₁₀](H₆SiW₁₂O₄₀)Cl₂·18H₂O (2-Ln, Ln = Sm, Eu, Gd, Tb, Dy, Ho, Er) have been obtained. Single-crystal structural analyses show that 1-Ln and 2-Ln constitute the first cases of Cr–Ln heterometallic clusters stabilized by inorganic polyoxometalate anions and organic ligands. Optical spectra studies demonstrate that 1-Ln and 2-Ln are narrow-gap semiconductors with band gaps of about 1.5 eV. Magnetic investigation shows that compound 2-Dy is a potential single molecule magnet.

By introduction of trilacunary Keggin-type polyoxometalate to the hydrothermal reaction system of Cr³⁺, Ln³⁺ and phthalic acid, a series of novel {Cr₄Ln₄} heterometallic clusters have been obtained.