{Cu8} Cluster-Sandwiched Polyoxotungstates and Their Polymers: Syntheses, Structures, and Properties.

Four inorganic-organic hybrid octa-Cu cluster sandwiched polyoxotungstates (POTs), [Cu8(H2O)2(en)4(B-α-H2SiW9O34)2] (1), [Cu8(H2O)2(en)4(B-α-H2GeW9O34)2] (2), K2[Cu8(en)4(B-α-HSiW9O34)2]·6H2O (3), and K2[Cu8(en)4(B-α-HGeW9O34)2]·2H2O (4) (en = ethylenediamine), were hydrothermally made and characterized by single-crystal X-ray diffraction, infrared spectra, powder X-ray diffraction, and thermogravimetric analysis, respectively. Structure analysis reveals that the polyoxoanion of 1/2 is a discrete dimer built by two trivalent Keggin [B-α-XW9O34]10- (X = Si/Ge) fragments and one octa-Cu cluster, whereas 3 and 4 display a two-dimensional network built by octa-Cu-sandwiched POT units via substitution of coordinated water on polyanions of 1 and 2 and further expand into a three-dimensional framework via K cation bridges. Ultraviolet-visible diffuse reflectance spectra reveal that 1-4 are potential semiconductor materials. Moreover, its visible light-driven catalytic H2 evolution activity, electrochemical properties, catalysis for oxygenation reactions of thioethers, and magnetic behaviors have been investigated in detail.

Enantiomeric Polyoxometalates Based on Malate Chirality-Inducing Tetra-ZrIV-Substituted Keggin Dimeric Clusters.

On the basis of the synergistic strategy of lacunary polyoxometalate structure-directing function and chiral ligand inducting role, two pairs of enantiomeric polyoxotungstates, (NH4)4(TMA)4[Zr4(µ3-O)2(l-/d-mal)2(B-α-HSiW10O37)2] (TMA = tetramethylammonium, mal = malate (C4H5O5); l-mal for 1a, d-mal for 1b) and (NH4)4(TMA)4[Zr4(µ3-O)2(l-/d-mal)2(B-α-PW10O37)2] (l-mal for 2a, d-mal for 2b), and a mesomeric polyoxotungstate, (NH4)3Na2K5[Zr4(µ3-O)2(l-mal)(d-mal)(B-α-SiW10O37)2] (3), were hydrothermally synthesized. 1a, 2a and 1b, 2b respectively exhibit 1-D 21 right- and left-hand helical chains formed by hydrogen-bonding interactions, and 3 forms a 3-D (3,10)-connected framework by Na+/K+ ions with {418.624.83}{43}2 topology. These homochiral compounds represent the first examples of enantiomerically pure ZrIV-substituted Keggin POMs. In this system, {Zr4(µ3-O)2(l-/d-mal)2} clusters transfer chirality from d- or l-mal to Keggin polyoxotungstate dimeric clusters, which was demonstrated by structural comparison between the homochiral architecture and mesomer as well as circular dichroism spectra of enantiomers. UV-vis diffuse reflectance spectra reveal that 1-3 are potential semiconductor materials. In addition, 1 and 2 exhibit second harmonic generation response with their response intensities of 0.8 times that of KDP.

Two New Copper Borates with Mesoscale Cubic Supramolecular Cages Assembled from {Cu4 @B20 } Clusters.

Two new copper borates, namely H6 [(µ4 -O)Cu4 @B20 O32 (OH)8 ]⋅25 H2 O (1) and H6 [(µ4 -O)Cu4 @B20 O32 (OH)8 ]⋅34 H2 O⋅8 H3 BO3 (2), with 3D supramolecular framework have been made under solvothermal conditions, which built by novel cubic supramolecular cages with mesoscale cavities via the H-bondings. Interestingly, the cage is assembled by [(µ4 -O)Cu4 @B20 O32 (OH)8 ] ({Cu4 @B20 }) cluster units with different point-group symmetry. Owing to extra H3 BO3 molecules participated in building the supramolecular framework, 2 has a larger cubic cage size and higher non-framework volume, leading to the cage size extended to mesoporous size set as a version of ''1 plus".

CsBxGe6-xO12 (x = 1): A Zeolite Sodalite-Type Borogermanate with a High Ge/B Ratio by Partial Boron Substitution.

The partial replacement of Ge atoms in tetrahedral positions by a small number of B atoms leads to a new microporous borogermanate, CsBxGe6-xO12 (x = 1), under solvothermal conditions. Its framework shows the highest atomic ratios of Ge/B in reported borogermanates and leads to a new type of zeolite sodalite-type net.

Diverse Ligand-Functionalized Mixed-Valent Hexamanganese Sandwiched Silicotungstates with Single-Molecule Magnet Behavior.

Under hydrothermal conditions, replacement of the water molecules in the [Mn(III) 4 Mn(II) 2 O4 (H2 O)4 ](8+) cluster of mixed-valent Mn6 sandwiched silicotungstate [(B-α-SiW9 O34 )2 Mn(III) 4 Mn(II) 2 O4 (H2 O)4 ](12-) (1 a) with organic N ligands led to the isolation of five organic-inorganic hybrid, Mn6 -substituted polyoxometalates (POMs) 2-6. They were all structurally characterized by IR spectroscopy, elemental analysis, thermogravimetric analysis, diffuse-reflectance spectroscopy, and powder and single-crystal X-ray diffraction. Compounds 2-6 represent the first series of mixed-valent {Mn(III) 4 Mn(II) 2 O4 (H2 O)4-n (L)n } sandwiched POMs covalently functionalized by organic ligands. The preparation of 1-6 not only indicates that the double-cubane {Mn(III) 4 Mn(II) 2 O4 (H2 O)4-n (L)n } clusters are very stable fragments in both conventional aqueous solution and hydrothermal systems and that organic functionalization of the [Mn(III) 4 Mn(II) 2 O4 (H2 O)4 ](8+) cluster by substitution reactions is feasible, but also demonstrates that hydrothermal environments can promote and facilitate the occurrence of this substitution reaction. This work confirms that hydrothermal synthesis is effective for making novel mixed-valent POMs substituted with transition-metal (TM) clusters by combining lacunary Keggin precursors with TM cations and tunable organic ligands. Furthermore, magnetic measurements reveal that 3 and 6 exhibit single-molecule magnet behavior.

Lanthanide Germanate Cluster Organic Frameworks Based on {Ln8Ge12} Clusters: From One-Dimensional Chains to Two-Dimensional Layers and Three-Dimensional Frameworks.

Under hydrothermal conditions, six series of novel lanthanide (Ln) organogermanates (LnGs) [Ln8Ge12(µ3-O)24E12(H2O)16]·14H2O (Ln(3+) = Pr(3+), 1; Nd(3+), 2; Sm(3+), 3; Eu(3+), 4; Gd(3+), 5; one-dimensional (1-D) LnG cluster organic chain (LnGCOC)), {[Nd8Ge12(µ3-O)24E12(H2O)10](µ2-H2O)2[Nd8Ge12(µ3-O)24E12(H2O)16]}·18H2O (6, two-dimensional (2-D) planar LnG cluster organic layer (LnGCOL)), {[Ln2GeE(HO)2O(H2O)(CH3COO)2(CO3)]2[Ln8Ge12E12(µ3-O)24(H2O)10]}·6H2O (Ln(3+) = Pr(3+), 7; Nd(3+), 8; 2-D wave-shaped LnGCOL), [TbGeE(HO)2O(H2O)(pca)]2[Tb8Ge12E12(µ3-O)24(H2O)8]·10H2O (9, three-dimensional (3-D) LnG cluster organic framework (LnGCOF)), {([Nd(pza)2(H2O)2]2[Nd8Ge12E12(µ3-O)24(H2O)12])([Nd(pza)2]2[Nd8Ge12E12(Hpza)2(µ3-O)24(H2O)10])}·4OH·14H2O (10, 3-D LnGCOF), {[Nd8Ge12E12(µ3-O)24(H2O)10][Nd(pca)(pda)(H2O)]2}·12H2O (11, 3-D LnGCOF) and {[Nd8Ge12E12(µ3-O)24(H2O)10][Nd(pza)(pda)(H2O)]2}·12H2O (12, 3-D LnGCOF) (Hpca = 2-picolinic acid, H2pda = 2,6-pyridinedicarboxylic acid, Hpza = 2-pyrazinecarboxylic acid) were prepared by introducing the second auxiliary ligands into the organogermanate-lanthanide-oxide reaction system. The obtainment of these LnGs realized the utilization of the second auxiliary ligands inducing the assembly from 1-D LnGCOCs to 2-D LnGCOLs and 3-D LnGCOFs based on LnG cluster (LnGC) {Ln8Ge12E12(µ3-O)24(H2O)16}({Ln8Ge12}) units and Ln-organic complexes or organic ligand connectors. It should be noted that the well-organized structural constructions of 1-12 can be visualized as the gradual replacement of active water sites located at equatorial and polar positions on the hypothetical [Ln8Ge12(µ3-O)24E12(H2O)18] LnGC core with oxygen or nitrogen atoms from organic ligands. The solid-state luminescent properties of 2, 3, 4, 6, and 8-12 have been investigated at room temperature.

A Series of Aluminoborates Templated or Supported by Zinc-Amine Complexes.

A series of open-framework aluminoborates (ABOs), namely, [Zn2 (en)5 ][Al2 B10 O20 ] (1), [Zn(en)(dien)][AlB5 O10 ] (2), [Zn(en)3 ][AlB7 O12 (OH)2 ] (3), [Zn(en)2 ][AlB5 O10 ] (4), K7 {AlO0.5 [BO2 (OH)]Zn@[B12 O21 (OH)3 ]}⋅H2 O (5) (en=ethylenediamine, dien=diethylenetriamine) have been made under mild solvothermal conditions and characterized by single-crystal X-ray diffraction, powder X-ray diffraction, elemental analysis, IR and UV/Vis spectroscopy, thermogravimetric analysis, and nonlinear optical determination. They were classified as two types: Compounds 1-4 contain intersecting channels and exhibit various 4-connected nets built by AlO4 tetrahedra and oxo boron clusters, zinc-amine complexes act as the templates (1-3) or directly bond to the walls of the ABO (4); compound 5 exhibits a double-layer structure made by nanosized [BO2 (OH)]Zn@[B12 O21 (OH)3 ] ({BZn@B12 }) clusters with Al2 O7 dimers, the channels are within the layer. The second harmonic generation (SHG) measurement shows that the SHG responses of 1-3 are about 2.5, 1.6, and 0.5 times that of KH2 PO4 . Compounds 1-2 are type I phase-matchable materials. UV/Vis spectroscopy indicates that compounds 1-5 are wide-band-gap semiconductors.

A 3D aluminoborate open framework interpenetrated by 2D zinc-amine coordination-polymer networks in its 11-ring channels.

A new inorganic-organic hybrid solid, [Zn(dap)2 ][AlB5 O10 ], combining the structural features of 3D open-framework inorganic solids and 2D metal-organic coordination polymers has been synthesized under solvothermal conditions. The compound displays extensive luminescence and moderate second-harmonic-generation efficiency.

Three new mixed-alkali- and alkaline-earth-metal borates: from 1D chain to 2D layer to 3D framework.

Three new mixed-metal borates, K4Ba2[B14O20(OH)10]·3H2O (1), LiSr2[B10O16(OH)3] (2), and LiBa[B9O15] (3), have been made under hydro(solvo)thermal conditions and characterized by means of IR, UV-vis-near-IR, thermogravimetric analysis, powder X-ray diffraction, and single-crystal X-ray diffraction, respectively. 1 is a 1D chain constructed from B14O21(OH)10(10-) cluster units, 2 is of a 2D layer with nine-membered-ring windows built up of B10O19(OH)3(9-) cluster units, while 3 exhibits a 3D framework with 12-membered-ring channels composed of B3O7 cluster units.

A new tetra-Zr(iv)-substituted polyoxotungstate aggregate.

A new tetra-Zr-substituted tungstophosphate (TP), [H2N(CH3)2]6Na6H8{Zr2[SbP2W4(OH)2O21][α2-PW10O38]}2·50H2O (1), has been made by the hydrothermal reaction of the [B-α-SbW9O33]9- building block with Zr4+ cations and PO43- anions in the presence of dimethylamine hydrochloride and NaOAc-HOAc (pH = 4.8), and further characterized by IR spectroscopy, elemental analysis, thermogravimetric analysis (TGA), powder X-ray diffraction (PXRD), 31P NMR spectroscopy and single-crystal X-ray diffraction. 1 is a toroidal structure formed by two divacant [α2-PW10O38]11- units and two [SbP2W4(OH)2O21]7- fragments linked by four Zr4+ cations. Note that the TP is reassembled with tetrahedral PO4 replacing the triangular pyramidal SbO3 in the [B-α-SbW9O33]9- precursor. In addition, the pendant SbO3 derives from the dissociation of the [B-α-SbW9O33]9- precursor. Furthermore, the electrochemical properties of 1 have been studied in Na2SO4 + H2SO4 supporting electrolyte (0.5 mol L-1), and indicate that 1 exhibits apparent catalytic activity toward H2O2 and BrO3- reduction. The 31P NMR spectrum of 1 exhibits three signals with approximately proportional intensities, which is consistent with the solid-state structure.

A series of lanthanide germanate cluster organic frameworks.

Six new lanthanide (Ln) germanate cluster organic frameworks (LnGeCOFs) derived from {Ln8Ge12} cage cluster units {[Nd(pza)2(H2O)] [Nd8Ge12(µ3-O)24E12(pza)(H2O)12]}·3H2O (1), {[Dy(CH3COO)(CO3)(H2O)]2[Dy8Ge12(µ3-O)24E12(H2O)12]}·11H2O (2), {[TbGeE(HO)2O(pza) (H2O)]2[Tb8Ge12(µ3-O)24E12(H2O)6]}·18H2O (3), {[DyGeE(HO)2O(C3H5NO2)(H2O)]2[Dy8Ge12(µ3-O)24E12(H2O)8]}·8H2O (4), {[Tb(pca)2 (H2O)]3[Tb8Ge12(µ3-O)24E12(H2O)4]}·(OH)3·10H2O (5) and {[Dy(pza)2(H2O)][Dy(pza)2(H2O)2][Dy(pza)3(H2O)][Dy8Ge12(µ3-O)24E12(pza)(HCOO) (H2O)6]}·5H2O (6) have been hydrothermally synthesized and structurally characterized. Increasing the amount of the second ligands can induce not only the assembly from 1 to 5, 6 based on Ln oxides as the starting sources, but also the assembly from 2 to 3, 4 based on Ln salts as the starting sources. The successful preparation of these LnGeCOFs suggests the importance of the second ligands in the structural construction of 1-6. To our knowledge, 1 is the first example that includes right- and left-handed helical chains among LnGeCOFs based on bis(carboxyethylgermanium)sesquioxide. 2, 4 and 6 are the first dysprosium incorporated organogermanates based on bis(carboxyethylgermanium)sesquioxide. 4 and 5 display very open framework structures with a solvent-accessible volume of 34.6% for 4 and 35.0% for 5. Moreover, the solid-state photoluminescence properties of 1, 3 and 5 have been investigated at room temperature and they exhibit the characteristic emission bands derived from Ln cations.

Two novel pillared-layer lanthanide borates built by Ln@B12O28/29 ring clusters and dicarboxylate linkers (Ln = Pr, Nd).

Two organic-inorganic hybrid pillared-layer lanthanide borates, [Ln2B8O12(bdc)3(H2O)]·H2O (Ln = Pr, 1; Nd, 2; H2bdc = 1,4-benzene dicarboxylic acid), have been made, in which inorganic layers are built by Ln-centred oxoboron ring clusters, Ln@B12O28/Ln@B12O29, while the pillars are organic bdc linkers. Interestingly, two types of linkages, Ln-O-C and B-O-C bonds, exist in the structures, showing firstly novel linking modes between inorganic polyborate and organic dicarboxylate.

Series of open-framework aluminoborates containing [B5O10] clusters.

Three new open-framework aluminoborates (ABOs), Rb2AlB5O10·4H2O (), [C5N2H16]AlB5O10 (, C5N2H16 = N-ethyl-1,3-diaminopropane) and [H2dap][(CH3)2NH]AlB5O10 (, dap = 1,2-diaminopropane) have been made under solvothermal conditions and characterized by elemental analysis, IR, TGA, UV-vis, powder XRD, single-crystal XRD, fluorescence spectra and NLO determination, respectively. These three ABOs display two structural types: and are isostructural and crystallize in acentric space groups C2221 and P212121 respectively, showing intersecting helical channels and good NLO properties; while, crystallizes in the centrosymmetric space group Pbca and has CrB4 topology, exhibiting intersecting 8-, 11- and 14-ring channels. UV-vis spectral investigation indicates that they are wide-band-gap semiconductors.

Na2B10O17·H2en: a three-dimensional open-framework layered borate co-templated by inorganic cations and organic amines.

A layered borate Na2B10O17·H2en (1, en = ethylenediamine) with three-dimensional microporosity within the layers has been synthesized under solvothermal conditions by using organic amines and inorganic cations as the templates. Its framework displays a unique 5-connected net constructed by B5O11 cluster and emits blue luminescence.

Two organic-inorganic hybrid 3D {P(5)W(30)}-based heteropolyoxotungstates with transition-metal/Ln-carboxylate-Ln connectors.

Two unique organic-inorganic hybrid polyoxometalates constructed from Preyssler-type [Na(H2 O)P5 W30 O110 ](14-) ({P5 W30 }) subunits and TM/Ln-carboxylate-Ln connectors (TM=transition metal, Ln=lanthanide), KNa7 [{Sm6 Mn(µ-H2 O)2 (OCH2 COO)7 (H2 O)18 }{Na(H2 O)P5 W30 O110 }]⋅22 H2 O (1) and K4 [{Sm4 Cu2 (gly)2 (ox)(H2 O)24 }{NaP5 W30 O110 }]Cl2 ⋅25 H2 O (2; gly=glycine, ox=oxalate) have been hydrothermally synthesized and characterized by elemental analyses, IR spectra, UV/Vis-NIR spectra, thermogravimetric analyses, power X-ray diffraction, and single-crystal X-ray diffraction. Compound 1 displays one interesting 3D framework built by three types of subunits, {P5 W30 }, [Sm2 Mn(µ-H2 O)2 (OCH2 COO)2 (H2 O)5 ](4+) , and [Sm4 (OCH2 COO)5 (H2 O)13 ](2+) , whereas 2 also manifests the other intriguing 3D architecture created by three types of subunits, {P5 W30 }, [SmCu(gly)(H2 O)8 ](4+) , and [Sm2 (ox)(H2 O)8 ](4+) . To our knowledge, 1 and 2 are the first 3D frameworks that contain {P5 W30 } units and TM/Ln-carboxylate-Ln connectors. The fluorescent properties of 1 and 2 have been investigated.