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Two copper-complex-substituted tungstogermanates [Cu5(2,2'-bpy)6(H2O)][GeW8O31].9H2O, 1, and {[Cu5(2,2'-bpy)5(H2O)][GeW9O34]}2.7H2O, 2 (2,2'-bpy = 2,2'-bipyridyl), have been hydrothermally synthesized and structurally characterized. X-ray structural analyses show that 1 is a rare tetralacunary Keggin anion of [B-beta-GeW8O31]10- substituted by copper complexes, while dimer 2 consists of two trilacunary [B-alpha-GeW9O34]10- Keggin units bridged by copper complexes. Magnetic measurement for 2 shows the presence of antiferromagnetic interactions within the dinuclear Cu2+ cations.

The combination of polyoxoniobates (PONbs) with 3d metal ions, azoles, and organoamines is a general synthetic procedure for making unprecedented PONb metal complex cage materials, including discrete molecular cages and extended cage frameworks. By this method, the first two PONb metal complex cages K4@{[Cu29(OH)7(H2O)2(en)8(trz)21][Nb24O67(OH)2(H2O)3]4} and [Cu(en)2]@{[Cu2(en)2(trz)2]6(Nb68O188)} have been made. The former exhibits a huge tetrahedral cage with more than 120 metal centers, which is the largest inorganic–organic hybrid PONb known to date. The later shows a large cubic cage, which can act as building blocks for cage‐based extended assembly to form a 3D cage framework {[Cu(en)2]@{[Cu2(trz)2(en)2]6[H10Nb68O188]}}. These materials exhibit visible‐light‐driven photocatalytic H2 evolution activity and high vapor adsorption capacity. The results hold promise for developing both novel cage materials and largely unexplored inorganic–organic hybrid PONb chemistry. [ABSTRACT FROM AUTHOR]

Abstract: Combination of in-situ generated monocopperII-substituted Keggin polyoxoanions with copperII–organoamine complexes under hydrothermal conditions results in seven inorganic–organic composite polyoxotungstates [Cu(en)2(H2O)]2{[Cu(en)2][α-PCuW11O39Cl]}·3H2O (1), {[Cu(en)2(H2O)][Cu(en)2]2[α-PCuW11O39Cl]}·6H2O (2), {[Cu(en)2(H2O)]2[Cu(en)2][α-XCuW11O39]}·5H2O (3/4, X=SiIV/GeIV), {[Cu(deta)(H2O)2]2[Cu(deta)(H2O)][α-XCuW11O39]}·5H2O (5/6, X=GeIV/SiIV) and [Cu(dap)2]2{[Cu(dap)2]2[Cu(dap)2][α-PCuW11O39]2} (7) (en=ethylenediamine, dap=1,2-diaminopropane and deta=diethylenetriamine). 1 is an isolated structure whereas 2 is a 1-D chain structure, but both contain [α-PCuW11O39Cl]6− polyoxoanions. 3–6 contain the 1-D linear chains made up of [α-XCuW11O39]6− polyoxoanions in the pattern of –A–A–A– (A=[α-XCuW11O39]6−), while 7 demonstrates the first 1-D zigzag chain constructed from [α-PCuW11O39]2 10− polyoxoanions via [Cu(en)2]2+ bridges in the pattern of –A–B–A–B– (A=[α-PCuW11O39]2 10−, B=[Cu(en)2]2+). The successful syntheses of 1–7 can provide some experimental evidences that di-/tri-/hexa-vacant polyoxoanions can be transformed into mono-vacant Keggin polyoxoanions under hydrothermal conditions. [Copyright &y& Elsevier]

Abstract: Two new Dawson-based phosphotungstates (H2en)0.5H[Cu(en)2(H2O)]2{[Cu(en)2](α 1-P2W17CuO61)}·8H2O (1) (en=ethylenediamine) and [4,4′-H2bpy]2{[Cu(4,4′-bpy)3][Cu(4,4′-bpy)4(H2O)2]2[Cu(4,4′-bpy)][α-P2W18O62]2}·6H2O (2) (4,4′-bpy=4,4′-bipyridine) have been hydrothermally synthesized and structurally characterized. 1 crystallizes in the triclinic space group P−1 with a=11.7626(17), b=13.246(2), c=29.350(5)Å, α=87.355(5), β=79.583(5), γ=66.993(3)°, V=4138.3(11)Å3, Z=2, GOF=1.089, R 1=0.0563 and wR 2=0.1505, whereas 2 belongs to the orthorhombic space group Iba2 with a=22.277(8), b=47.04(2), c=22.153(8)Å, V=23215(17)Å3, Z=4, GOF=1.051, R 1=0.0627 and wR 2=0.1477. 1 consists of a 1-D linear chain structure constructed from monocopperII-substituted Dawson polyoxoanions, while 2 represents the first 2-D sheet-like structure with a (4,4)-connected topological net built up from plenary Dawson-type polyoxoanions and CuII-4,4′-bpy complex cations in polyoxometalate chemistry. [Copyright &y& Elsevier]

Abstract: A novel di-copperII-complex substituted monovacant Keggin polyoxotungstate [Cu(2,2′-bpy)(H2O)][H2PW11O39Cu2(2,2′-bpy)2(H2O)(OH)]·1.5H2O (1) (2,2′-bpy=2,2′-bipyridine) with a 1D polymeric chain has been hydrothermally synthesized and structurally characterized. To our knowledge, 1 is the rare magnetic di-transition metal-complex substituted monovacant Keggin polyoxotungstate with a unique 1D dual-bridging chain structure. Its magnetic behavior has been quantitatively analyzed by the Bleaney–Bowers equation, indicating the presence of weak antiferromagnetic interactions within dinuclear CuII centers. [Copyright &y& Elsevier]

A novel guanidine-containing polyoxotantalate (POTa), H 12 [CN 3 H 6 ] 12 Na 2 (H 2 O) 6 [Cu(en) 2 (H 2 O)] 3 [Ta 6 O 19 ] 4 ·32H 2 O (1) has been synthesized by adding the CH 6 N 3 + as counter cations. The [Ta 6 O 19 ]8− clusters in compound 1 are connected by sodium ions to form a 2-D layered structure, which is further connected through [Cu(en) 2 (H 2 O)]2+ to form a 3-D supramolecular framework structure. Moreover, it is demonstrated that compound 1 exhibits reversible thermochromism behavior, changing from purple to dark blue upon heating and dehydration, which endows it with potential application in the field of anti-counterfeiting functional materials. Organic guanidine cations were first introduced as charge compensation ions to isolate a novel polyoxotantalate compound with 3-dimensional supramolecular framework structure and reversible thermochromism behavior upon heating and dehydration. [Display omitted] • A new inorganic-organic hybrid POTa was synthesized and characterized. • The compound exhibits an interesting 3-dimensional supramolecular framework structure with huge nanoscale channels. • Discrete POTa clusters and organic guanidine cations coexist to stabilize the 3-dimensional supramolecular framework. • The compound exhibits reversible thermochromism behavior upon heating and dehydration. • This work enriches the structural diversity of POTas and provides a new idea for new anti-counterfeiting materials. [ABSTRACT FROM AUTHOR]

A new inorganic-organic dimeric polyoxoniobate containing "S"-shaped {[Cu 3 (en) 6 (β-H 4 Nb 52 O 150) 2 } polyoxoanion was prepared and characterized. • A new inorganic-organic dimeric polyoxoniobate contains "S"-shaped {[Cu 3 (en) 6 (β-H 4 Nb 52 O 150) 2 } polyoxoanions. • Novel high-nuclearity {β-H 4 Nb 52 O 150 } cluster enriches the limited structures of the polyoxoniobate family. • The compound 1 shows effective catalytic activity for hydrolytic decomposition of nerve agent simulant DMMP. A new inorganic-organic hybrid polyoxoniobate, H 16 K 24 Na 26 [Cu 3 (en) 6 [(β -H 4 Nb 52 O 150) 2 ·88H 2 O (1) (en = ethylenediamine), decorated with [Cu(en) 2 2+ complex, has been hydrothermally synthesized and structurally characterized by single-crystal X-ray diffraction, IR, and Uv-vis. Crystal structure analysis shows that 1 contains a "S"-shaped {[Cu 3 (en) 6 (β -H 4 Nb 52 O 150) 2 } polyoxoanion which is built from novel high-nuclearity {[Cu(en) 2 (β-H 4 Nb 52 O 150)} fragments. The compound 1 shows effective catalytic activity for hydrolytic decomposition of nerve agent simulant of dimethyl methylphosphonate (DMMP). [ABSTRACT FROM AUTHOR]