| The main aim of the paper is to design and prepare some novel polymolybdates and Keggin polytungstates. The former is to prepare polymolybdates coordinated' directly by organic ligands using Na2MoO4 and MoO3 precursors; The latter plays emphasis on exploiting a simple and effective routine to synthesize Keggin polytungstates in which the transition metal or Si acts as the heteratom by reaction precursor Na2WO4.We have synthesized a 4,4'-bipyridine bridging dumbbell-like polymolybdates a metatungstate three Keggin-type polytungstates in which the heteroatom are transition metal and two mono-substituted Keggin tungstosilicates. Their main crystal data, structure feature and properties are listed as following:1. A 4,4'-bipyridine bridging dumbbell-like dimeric pentamolybdate: [4,4'-H2bipy]3[4,4'-Hbipy]2[(Mo5On)2(4,4'-bipy)]Triclinic, P1 space group with a = 10.578(2) A, b = 11.047(2) A, c - 16.576(3), a = 79.86(3)2,B = 75.34(3)°, r=79.40(3)°, V= 1824.8(6) A3, Z = 1,DC = 2.221 gcm-3, u = 1.757 mm-1, R = 0.0255, Rw = 0.0578. In the complex two [Mo5O17]4- ion units are buttressed by a 4,4'-bipyridine ligand to form a dumbbell-like polyanion [(Mo5O17)2(4,4'-bipy)]8-. Thermal analysis indicate that anion [MO5O17]4- begin discompose at 409℃.2. Ametatungstate: [Cu(2,2'-bipy)3]2H2[H2W12O40] 4.5H2OTriclinic, Pi space group, a = 13.929(3) A, b = 17.493(4) A, c = 19.210(4) A, a = 86.39(3)°, B = 68.77 (3)°, r = 74.21(3)°, V= 4195.2(15) A3, Z= 2, Dc = 3.158 g cm-3, u = 16.970 mm-1, R= 0.0785, Rw = 0.0972. The compound is composed of one metatungstate anion, two copper-bipyridyl cations and four and a half crystallography water molecules.3. a-Keggin unit supported zinc-bipyridyl complex: [Zn(2,2'-bipy)3]2[ZnW12O40 Zn(2,2'-bipy)2] H2OTriclinic, P2(1)/n space group, a = 26.257(5) A, b = 13.877(3) A, c = 28.451(6), B = 97.83(3)°, V= 10270(4) A3, Z= 4, Dc = 2.831gcm-3,u = 14.381mm-1, R= 0.0660, Rw = 0.1065. In the novel polyanion [ZnW12O40Zn(2,2'-bipy)2]6-, the Keggin anion [ZnW12O40]6- acts as a bidentate ligand towards [Zn (2,2'-bipy)2]2+ cation through a terminal oxygen and a bridging oxygen.4. A Keggin-type tungstozincates (4,4'-H2bipy)2(4,4'-Hbipy)2(ZnW12O40) 6H2O Triclinic, P21/c space group, a = 18.637(4) A, b = 14.003(3) A, c = 26.470(5) A, B = 104.78(3)°, V=6680(2)A3,Z = 4, Dc = 3.630gcm-3,u = 21.032mm-1,R = 0.0651,Rw = 0.0606. The thermal analysis shows that Keggin anion [ZnW12O40]6- start to decompose at 587℃.5. A Keggin-type tungstocobaltate: [Co(2,2'-bipy)3]2H2[CoW12O40] 9.5H2O Triclinic, P1 space group, a = 14.482(3) A,b = 17.520(4) A, c = 19.177(4) A, a = 80.98(3)° B = 69.67(3)°, r =71.31(3) V= 4316.2(15) A3, Z= 2, Dc = 3.179gcm-3, u = 16.580 mm-1, R - 0.0513, Rw = 0.1205. EPR spectra reveal two Co2+ coordination environments: high spin state (g = 5.1, 4.2) and low spin state (g = 2.0) exhibiting in the title compound. Furthermore, when the temperature increases from 110K to room temperature, the signal g = 5.1 of high spin Co2+ disappears caused by the zero-field splitting. Thermal analysis indicates that Keggin anion skeleton begin to discompose at 560.4℃.6. A nickel substituted Keggin tungstosilicate: [Ni(DETA)2]3[SiNiW11O39]-2.5 H2OMonoclinic, Pn space group, a = 10.926(2) A, b = 23.022(5) A, c = 13.221 (3) A, B = 94.27(3)°, V= 3316.4(11)A3,Z = 2, Dc= 3.579gcm-3,u = 20.216, R=0.0515, Rw - 0.1142. [SiNiW11O40]6- unit connects with other adjacent units via Ni-O-Wbridges constructing an infinitely one-dimensional chain-like structure.7. A sodium substituted Keggin tungstosilicate: [H2en]2[Ba0.15(H2O)2(Hen2)]H1.7[SiNaW11O39] 2H2OMonoclinic, P21 space group, a = 12.840(3) A, b = 11.174(2) A, c = 16.693(3) A, B= 91.14(3)°, V= 2394.4(8) A3,Z= 2,DC = 4.231 gcm-3,u = 26.574, R= 0.0583, Rw- 0.1392. [SiNaW11O40]7- unit connects with other adjacent units via Na-O-Wbridges constructing an infinitely one-dimensional chain-like structure.ConclusionsA 4,4'-bipyridine bridging dumbbell-like dimeric penta...
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