Synthesis, Structure And Properties Of Rare-Earth Metals Constructed Organic-Inorganic Polyoxometalates And Transition-Metals Substituted Sandwich-type Germanomolybdates

The paper can be divided into two parts. In the first part, on the basis of molecular design and assembly, adopting rare-earth metals cations and carboxylate ligands, fifteen novel rare-earth metals constructed organic-inorganic polyoxometalates were successfully synthesized by conventional aqueous method and characterized by X-ray single–crystal diffraction, spectroscopic properties (IR, UV and XRD), thermal properties (TG) and fluorescence properties.I. Rare-earth metals constructed organic-inorganic polyoxometalates exhibiting three-dimensional frame structures. The structural analyses indicate that 1⁹ are basically isostructural and show a 3D framework containing Keggin polyoxoanions [SiW₁₂O₄₀]4– as templates. The photoluminescence measures reveal that 9 shows obvious red luminescence.1. [Tm(pydc)(H₂O)₃]₄[SiW₁₂O₄₀]·4H₂O: tetragonal system, I4(1)/a space group, a = 21.751(3) (A|·), b = 21.751(3) (A|·), c = 16.1438(15) (A|·), V = 7637.7(17) (A|·)3, Z = 4, R1 = 0.0320, wR2 = 0.0700.2. [Y(pydc)(H₂O)₃]₄[SiW₁₂O₄₀]·4H₂O: tetragonal system, I4(1)/a space group, a = 21.8154(9) (A|·), b = 21.8154(9) (A|·), c = 16.1967(12) (A|·), V = 7708.2(7) (A|·)3, Z = 4, R1 = 0.0489, wR2 = 0.1232.3. [Tb(pydc)(H₂O)₃]₄[SiW₁₂O₄₀]·4H₂O: monoclinic system, C2/c space group, a = 30.629(9) (A|·), b = 16.224(4) (A|·), c = 21.792(6) (A|·),β= 134.334(7)°, V = 7746(4) (A|·)3, Z = 4, R1 = 0.0710, wR2 = 0.1822.4. [Dy(pydc)(H₂O)₃]₄[SiW₁₂O₄₀]·4H₂O: tetragonal system, I4(1)/a space group, a = 21.776(4) (A|·), b = 21.776(4) (A|·), c = 16.138(5) (A|·), V = 7653(3) (A|·)3, Z = 4, R1 = 0.0707, wR2 = 0.1838. 5. [Gd(pydc)(H₂O)₃]₄[SiW₁₂O₄₀]·4H₂O: monoclinic system, C2/c space group, a = 30.487(2) (A|·), b = 16.3460(9) (A|·), c = 21.8505(13) (A|·),β= 134.24°, V = 7801.6(8) (A|·)3, Z = 4, R1 = 0.0518, wR2 = 0.1227.6. [Pr(pydc)(H₂O)4]4[SiW₁₂O₄₀]·4H₂O: tetragonal system, I4(1)/a space group, a = 21.9314(10) (A|·), b = 21.9314(10) (A|·), c = 16.7059(15) (A|·), V = 8035.3(9) (A|·)3, Z = 4, R1 = 0.0309, wR2 = 0.0669.7. [La(pydc)(H₂O)4]4[SiW₁₂O₄₀]·4H₂O: tetragonal system, I4(1)/a space group, a = 21.9285(8) (A|·), b = 21.9285(8) (A|·), c = 16.7265(12) (A|·), V = 8043.1(7) (A|·)3, Z = 4, R1 = 0.0247, wR2 = 0.0521.8. [Sm(pydc)(H₂O)4]4[SiW₁₂O₄₀]·4H₂O: tetragonal system, I4(1)/a space group, a = 21.685(5) (A|·), b = 21.685(5) (A|·), c = 16.470(7) (A|·), V = 7745(4) (A|·)3, Z = 4, R1 = 0.0311, wR2 = 0.0726.9. [Eu(pydc)(H₂O)4]4[SiW₁₂O₄₀]·4H₂O: tetragonal system, I4(1)/a space group, a = 21.7777(7) (A|·), b = 21.7777(7) (A|·), c = 16.4167(10) (A|·), V = 7785.9(6) (A|·)3, Z = 4, R1 = 0.0300, wR2 = 0.0714.II. Rare-earth metals constructed organic-inorganic polyoxometalates exhibiting two-dimensional layer structure. In compound 10, the polyoxoanions [SiW₁₂O₄₀]4– connect rare earth cations through terminal oxygen atoms forming a (4, 4)-connected 2D topology structure.10. [Y(pydc)(H₂O)3]2H2[SiW₁₂O₄₀]·4H₂O: orthorhombic system, Pnma space group, a = 25.792(2) (A|·), b = 16.3573(13) (A|·), c = 13.6352(11) (A|·), V = 5752.5(8) (A|·)3, Z = 4, R1 = 0.0415, wR2 = 0.0878.III. Rare-earth metals constructed organic-inorganic polyoxometalates exhibiting one-dimensional chain structure. In compounds 11 and 12, rare earth cations connect each other through pyridine-3, 4-dicarboxylate ligands forming 1D chain structure, in addition, the polyoxoanions [SiW₁₂O₄₀]4– connect the rare earth coordinated cation chains via weak K–O to form a 2D layer.11. {[Pr(H₂O)3][K(H₂O)2](pydc)2}2H4[SiW₁₂O₄₀]·2H₂O: triclinic system, P–1 space group, a = 10.8200(11) (A|·), b = 11.1094(12) (A|·), c = 16.9290(17) (A|·),α= 80.845(2)°,β= 79.699(2)°,γ= 61.9120(10)°, V = 1759.7(3) (A|·)3, Z = 1, R1 = 0.0464, wR2 = 0.1150.12. {[Nd(H₂O)3][K(H₂O)2](pydc)2}2H4[SiW₁₂O₄₀]·2H₂O: triclinic system, P–1 space group, a = 10.848(3) (A|·), b = 11.156(3) (A|·), c = 16.983(4) (A|·),α= 80.890(4)°,β= 79.719(4)°,γ= 62.013(3)°, V = 1779.2(7) (A|·)3, Z = 1, R1 = 0.0494, wR2 = 0.1218. IV. Rare-earth metals constructed organic-inorganic polyoxometalates exhibiting isolated structure. In coumpounds 13¹5, the polyoxoanions [PMo12O40]3– combine rare earth coordinated cations through electrostatic forces.13. [Pr(pydc)(H₂O)6]2H[PMo12O40]·4H₂O: tetragonal system, I4(1)/a space group, a = 15.2194(11) (A|·), b = 15.2194(11) (A|·), c = 28.481(4) (A|·), V = 6597.1(12) (A|·)3, Z = 4, R1 = 0.0673, wR2 = 0.1673.14. [Nd(pydc)(H₂O)6]2H[PMo12O40]·4H₂O: tetragonal system, I4(1)/a space group, a = 15.3257(14) (A|·), b = 15.3257(14) (A|·), c = 28.485(5) (A|·), V = 6690.5(14) (A|·)3, Z = 4, R1 = 0.0454, wR2 = 0.1181.15. [Tb(pydc)(H₂O)6]2H[PMo12O40]·4H₂O: tetragonal system, I4(1)/a space group, a = 15.2768(16) (A|·), b = 15.2768(16) (A|·), c = 28.337(6) (A|·), V = 6613.2(17) (A|·)3, Z = 4, R1 = 0.0612, wR2 = 0.1623.In the second part, on the basis of molecular design and assembly, adopting simple materials replacing lacunary heteropolymolybdate precursor, six novel transition-metal substituted sandwich-type germanomolybdates were synthesized by conventional aqueous method, diffusion method and hydrothermal technique, and characterized by X-ray single–crystal diffraction, spectroscopic properties (IR, UV, XRD and XPS), thermal properties (TG), surface photovoltage spectroscopy (SPS) and magnetic properties.I. Dinuclear transition-metal substituted sandwich-type germanomolybdates. SPS and EFISPS measurements reveal that 16 bear the behavior of the n-type semiconductor, magnetic measurements indicate 16 demonstrate antiferromagnetic exchange interactions.16. [Na12(H₂O)36][Cu2(β–Y–GeMo9O33)2]·3H₂O: triclinic system, P–1 space group, a = 13.2369(8) (A|·), b = 13.5286(8) (A|·), c = 16.6405(13) (A|·),α= 73.2850(10)°,β= 66.56°,γ= 60.71°, V = 2368.4(3) (A|·)3, Z = 1, R1 = 0.0327, wR2 = 0.0862.17. [N(CH3)4]4[Na6(H₂O)24][Cr2(β–Y–GeMo9 O33)2]·7H₂O: triclinic system, P–1 space group, a = 13.3571(12) (A|·), b = 13.5019(12) (A|·), c = 18.4660(17) (A|·),α= 76.9310(10)°,β= 77.5830(10)°,γ= 61.0300(10)°, V = 2816.3(4) (A|·)3, Z = 1, R1 = 0.0249, wR2 = 0.0745.18. [Cu(en)2]2[Cu(en)2(H₂O)]2{[Cu(en)2]2[Cu2(β–Y–GeMo9O33)2]}·8H₂O: triclinic system, P–1 space group, a = 13.0503(14) (A|·), b = 14.0662(15) (A|·), c = 17.4386(19) (A|·),α= 79.750(2)°,β= 73.805(2)°,γ= 64.567(2)°, V = 2770.0(5) (A|·)3, Z = 2, R1 = 0.0506, wR2 = 0.1398.II. Tetranuclear transition-metal substituted sandwich-type germanomolybdates. SPS and EFISPS measurements reveal that 19 bear the behavior of the n-type semiconductor, magnetic measurements indicate 19 demonstrate ferromagnetic exchange interactions.19. [Na11(H₂O)25]H[Ni4(H₂O)2(α–B–GeMo9O34)2]·6H₂O: triclinic system, P–1 space group, a = 11.6135(8) (A|·), b = 12.8737(9) (A|·), c = 17.1160(17) (A|·),α= 97.3750(10)°,β= 107.0050(10)°,γ= 111.6240(10)°, V = 2193.2(3) (A|·)3, Z = 1, R1 = 0.0332, wR2 = 0.0911.20. [Na11(H₂O)25]H[Mn4(H₂O)2(α–B–GeMo9O34)2]·6H₂O: triclinic system, P–1 space group, a = 11.6756(10) (A|·), b = 12.9056(11) (A|·), c = 17.3437(15) (A|·),α= 97.3770(2)°, β= 106.8390(10)°,γ= 111.8450(10)°, V = 2238.1(3) (A|·)3, Z = 1, R1 = 0.0547, wR2 = 0.1338.21. [Na11(H₂O)25]H[Co4(H₂O)2(α–B–GeMo9O34)2]·6H₂O: triclinic system, P–1 space group, a = 11.584(3) (A|·), b = 12.856(4) (A|·), c = 17.173(7) (A|·),α= 97.380(6)°,β= 106.906(6)°,γ= 111.713(4)°, V = 2191.7(13) (A|·)3, Z = 1, R1 = 0.0601, wR2 = 0.1672.