Hydrothermal Synthesis, Structure And Properties Of Polyoxometalates Based On Saturated And Trivacant Keggin Heteropolyanions

A series of polyoxometalates based on Keggin, Dawson and trivacant Keggin polyanions were successfully synthesized by hydrothermal methods. The study on synthetic conditions for these polyoxometalates and characterization by X-ray crystallography, spectroscopic (IR,UV and XPS) and thermal properties (TG) were carried out.â… . The sandwich-type polyoxotungstates based on trivacant Keggin polyanions:1. Na₉H{(V^â…£O)₆[B-α-Te^â…£W_7.5V_1.5^â…£O₃₃]₂}·21H₂O, monoclinic, P2₁/c, a = 16.859(2) (?), b = 12.8308(16) (?), c = 24.5914 (19) (?),β= 124.023(5)°, V= 4408.8(8) (?), Z = 2, R₁ = 0.0676, wR₂ = 0.1412.2. (C₃H₁₂N₂)₅{(V^â…£O)₆[B-α-Te^â…£W_7.5V_1.5^â…£O₃₃]₂}·8H₂O, monoclinic, P2₁/n, a = 17.8836(8) (?), b = 13.7101(6) (?), c = 21.6004(10) (?),β= 109.0360(10)°, V= 5006.5(4) (?),Z = 2, R₁ = 0.0581, wR₂ = 0.1773.3. [Cu(C₃N₂H₁₀)₂]₂Na₂H₄{(V^â…£O)₆[B-α-Te^â…£W_7.5V_1.5^â…£O₃₃]₂}·12H₂O, triclinic, P-1,a = 13.300(3) (?), b = 13.325(3) (?), c = 16.980(4) (?), a = 83.519(3)°,β= 73.738(3)°,γ= 65.972(3)°, V= 2638.6(9) (?), Z= 1, R₁ = 0.0824, wR₂ = 0.1925.4. [Co(phen)]₂[Co(phen)₂(H₂O)]₂[Co_3.5W_0.5(phen)₄(H₂O)₃(B-β-SbW₉O₃₃)₂], monoclinic, P2₁/c, a = 18.1263(14) (?), b = 14.6753(11) (?), c = 29.648(2) (?),β= 95.2650(10)°, V = 7853.3(10) (?), Z = 2, R₁ = 0.0555, wR₂ = 0.0954.â…¡. The polyoxotungstates based on saturated Keggin and Dawson polyanions:5. [Cu^â… (en)₂(H₂O)]₂{GeW₁₂O₄₀[Cu^â…¡(en)₂]}·2.5H₂O, monoclinic, C2/c, a = 21.3268(10) (?), b = 12.4534(5) (?), c = 44.441(2) (?),β= 93.4920(10)°, V= 11781.2(9) (?), Z= 8, R₁ = 0.0455, wR₂ = 0.0998. 6. [Fe^â…¢(phen)₃]₂(OH)[Fe^â…¢W₁₂O₄₀]·H₂O, triclinic, P1, a = 12.4483(8) (?), b =14.0367(9) (?), c = 14.3264(9) (?), a = 105.1830(10)°, (3 = 92.8630(10)°,γ= 97.4100(10)°, V= 2386.6(3) (?). Z= 1,R₁ = 0.0483, wR₂ = 0.1252.7. [Cu₂(2,2'-bipy)₂(H₂O)₂]₂{Cu₂(2,2'-bipy)₂(H₂O)₃[As₂W₁₈O₆₂]}·H₂O, monoclinic, P2₁/n, a = 20.499(3) (?), b = 16.890(3) (?), c = 26.330(4) (?), (3 = 109.484(2)°, V= 8594.2 (?), Z= 1, R₁ = 0.0876, wR₂ = 0.2555.â…¢. The molybdovanates based on [V₂Mo₆(OH)₂O₂₄]^4- and [VMo₁₂O₄₀]^3- polyanions:8. [Co(phen)₃]H₂[V₂Mo₆(OH)₂O₂₄]·7H₂O, monoclinic, C2/c, a = 13.4719(14) (?), b = 17.3696(17) (?), c =25.282(2) (?),β= 92.130(2)°, V= 5912.0(10) (?), Z = 4, R₁ = 0.0553, wR₂ = 0.1482.9. [Co(2,2'-bipy)₃][Na(H₂O)₇][VMo₁₂O₄₀], trigonal, R3c, a = b = 12.997(10) (?), c = 62.35(10) (?),γ= 120°, V= 9121.10 (?), Z = 6, R₁ = 0.0437, wR₂ = 0.0999.