Two Unprecedented Germanoniobate Frameworks Based on High-Nuclearity Peanut-Shaped {Ge12Nb38} Clusters

By variation of the amount of GeO2, two organic-inorganic hybrid germanoniobate frameworks with 6-connected pcu and 10-connected bct topologies were constructed from peanut-shaped {α-Ge12Nb38} and {β-Ge12Nb38} clusters, respectively. The {α-Ge12Nb38} and {β-Ge12Nb38} clusters contain the most Ge centers of germanoniobates reported so far. The compounds exhibit proton conduction properties with a conductivity of 3.04 × 10-4 S·cm-3 for 1 and 1.62 × 10-4 S·cm-3 for 2 at 85 °C and 98% RH. The water vapor adsorption capacities for 1 and 2 are 5.86 and 4.40 mmol·g-1, respectively.

Three Types of Lanthanide-Containing Polyoxoniobates and Their Luminescence Properties

Fourteen lanthanide (Ln)-containing hetero selenato-phosphato-peroxopolyoxoniobates in three series: (1) Cs₂{[Ln(H₂O)₄][H₄P₂Se₂Nb₆(O₂)₆O₂₂]}₂·nH₂O [Ln = Ce (I-Ce), Pr (I-Pr), Sm (I-Sm), Eu (I-Eu), Gd (I-Gd); I-Ce, I-Pr, I-Eu, I-Gd n = 12; I-Sm n = 16]; (2) Cs₂K₃{[Ln(H₂O)₆][H_2.5P₂Se₂Nb₆(O₂)₆O₂₂]}₂·nH₂O [Ln = Dy (II-Dy), Tm (II-Tm), Yb (II-Yb), Lu (II-Lu); II-Dy n = 14; II-Tm n = 24; II-Yb, II-Lu n = 13]; (3) Cs₅K₂H_m{[Ln(H₂O)₆][P₂Se₂Nb₆(O₂)₆O₂₂]}₂{[Ln_x(H₂O)_y]₂[P₂Se₂Nb₆(O₂)₆O₂₂]}·nH₂O [Ln = Ho (III-Ho), Er (III-Er), Tm (III-Tm), Yb (III-Yb), Lu (III-Lu), III-Ho-III-Yb m = 5, x = 1; y = 5; III-Lu m = 6.5; x = 0.75; y = 4; III-Ho-III-Tm n = 19, III-Yb n = 34; III-Lu n = 31], have been isolated by a one-pot reaction and structurally characterized by various physical and chemical analyses. These compounds represent the first group of Ln-functionalized polyoxoniobates with mixed heteroatoms. In addition, the photoluminescence properties of compounds I-Sm, I-Eu, and II-Dy were measured, and the time-resolved emission spectra showed that the {P₂Se₂Nb₆} segment contributed to the energy transfer from the polyoxoniobate units to the Ln³⁺ center, which effectively promoted the emission of the Ln³⁺ center.

Synthesis, structures and stability of three V-substituted polyoxoniobate clusters based on [TeNb9O33]17- units

Three structurally intriguing polyoxoniobates (PONbs) based on the trivacant B-type α-Keggin ion {TeNb9O33}, H4K(CN3H6)2{[Cu4(2,2'-bipy)4(H2O)2][TeNb9V2O37]}·29H2O (1, 2,2'-bipy = 2,2'-bipyridine), H0.5K5Na2.5{[Cu(en)H2O]3[TeNb9V3O39]}·10H2O (2, en = ethylenediamine), and K3Na5{[Cu(1,3-dap)H2O]3[TeNb9V3O39]}·11H2O (3, 1,3-dap = 1,3-diaminopropane), are assembled by the conventional aqueous solution methods using a series of N-containing organic ligands. In 1, each of the two {VO4} units is attached to two coplanar NbO6 octahedra on the {Nb3O13} cluster of the {TeNb9O33} unit. Differently, three {VO4} units in 2 and 3 are linked to two edge-sharing NbO6 octahedra, respectively. Compounds 1-3 represent the first oxo NbTeV clusters and also the first vanadoniobates based on the trivacant Keggin PONb units. All three compounds were characterised by single-crystal X-ray structural analysis, TGA and IR, ESI-MS and 51V NMR spectroscopy. Furthermore, the magnetic properties of compounds 1 and 2 were also studied.

A super stable assembled P nanowire with variant structural and magnetic/electronic properties via transition metal adsorption

By means of first-principles calculations, we systematically investigated the structure, stability and magnetic and electronic properties of one-dimensional P nanowire (1D-P10 NW) assembled by Pn subunits (n = 2, 8) and transition metal doped 1D-P10 NW. Our calculations showed that the assembled 1D-P10 NW is super stable in thermodynamic, dynamic, thermal and chemical perspectives. Moreover, when the assembled 1D-P10 NW is decorated with transition metals (TM = Ti ∼ Zn, Zr ∼ Mo), structural transformation occurs (to sandwich or quasi-sandwich chains), and various magnetic and electronic characteristics are introduced to the nanowire. Particularly, the sandwich chains 1D-Mn2@P10 and 1D-V1@P5 are a ferromagnetic semiconductor and a ferromagnetic half-metal, respectively, and the magnetic anisotropy energies are both ∼0.3 meV per Mn/V atom. Our theoretical studies proposed a super stable 1D P nanowire and also offer a feasible approach to reach P5-TM-P5-TM chains with diverse magnetic and electronic properties, as well as ferromagnetic vdW-type 2D systems, which are promising in nanoelectronic devices and spintronics.

Discovery of the selenotantalate building block and its lanthanide derivatives: design, synthesis, and RhB decolorization properties

Herein we present the first Se/Ta polyoxometalate and its lanthanide derivatives with good photocatalytic activity for the decolorization of RhB.

Synthesis, structure, and luminescent properties of a family of lanthanide-functionalized peroxoniobiophosphates

Eight new lanthanide derivatives containing 6-peroxoniobio-4-phosphate building block, [LnIII(H2O)6]2[H4(NbO2)6P4O24]·nH2O [Ln = Eu (1), Gd (2), Tb (3), Dy (4), Ho (5), Er (6), Tm (7), Yb (8), 1-5, 7, 8 n = 12; 6 n = 9], have been successfully obtained using an in-situ strategy and fully characterized in the solid state by single-crystal X-ray diffraction, IR spectra, TG-MS, PXRD. Structural analyses indicate that these isostructural polyanions 1-8 consist of one [P4(NbO2)6O24]10- (P 4 (NbO 2 ) 6 ) clusters and two pendant Ln3+ cations. In these compounds, P 4 (NbO 2 ) 6 clusters are connected by lanthanide cations to form extended two-dimensional architectures. The approach takes advantage of the ability of in-situ formed P 4 (NbO 2 ) 6 cluster to build frameworks by using it as ligands to lanthanide ions. The photoluminescence (PL) and lifetime decay behaviors of 1, 3 and 4 in solid state have been performed at room temperature. The PL emission of 1, 3 and 4 is mainly derived from the characteristic 5D0→7FJ (J = 1, 2, 3, 4), 5D4→7FJ (J = 6, 5, 4, 3) and 4F9/2→6H J (J = 15/2, 13/2, 11/2) transitions of the EuIII, TbIII and DyIII cations, respectively.