TY - JOUR
T1 - A combination of lacunary polyoxometalates and high-nuclear transition-metal clusters under hydrothermal conditions. Part II
T2 - From double cluster, dimer, and tetramer to three-dimensional frameworks
AU - Zhao, Jun Wei
AU - Jia, Hong Peng
AU - Zhang, Jie
AU - Zheng, Shou Tian
AU - Yang, Guo Yu
PY - 2007
Y1 - 2007
N2 - The hydrothermal reactions of trivacant Keggin A-α-XW 9O34 polyoxoanions (X = PV/SiIV) with transition-metal ions (NiIICuII/FeII) in the presence of amines result in eight novel high-nuclear transition-metal- substituted polyoxotungstates [{Ni7(μ3-OH) 3O2-(dap)3(H2O)6}(B- αPW9O34)[{Ni6(μ3-OH) 3(dap)3(H2O)6}(B-α-PW 9O34)][Ni-(dap)2(H2O) 2]·4.5H2O (1), [Cu(dap)-(H2O) 3]2[{Cu8(dap)4(H2O) 2}(B-α-SiW9- O34)2] ·6H2O (2), (enH2)3H 15[{Fe1.5II -Fe12 III(μ3-OH)12(μ4-PO 4)4}(B-α-PW9-O34) 4]·ca.130H2O (3), [{Cu6(μ 3-OH)3-(en)3 (H2O) 3}(B-α-PW9O34)]·7H2O (4), [{Ni6(μ3-OH)3(en)3(H 2O)6}(B-α-PW9- O34)] ·7H2O (5), [(Ni6(μ3-OH) 3(en)2-(H2O)8}(B-α-PW 9O34)]·7H2O (6), [{(Ni 6-(μ3-OH)3(dap)2(H 2O)8}(B-α-PW9O34)]· 7H2O (7), and [{Ni6(μ3-OH) 3(en)3- (H2O)6}(B-α-SiW 9O34)][Ni0.5(en)]· 3.5 H2O (8) (en = ethylenediamine, dap = 1,2-diaminopropane). These compounds have been structurally characterized by elemental analyses, IR spectra, diffuse reflectance spectra, thermogravimatric analysis, and X-ray crystallography. The double-cluster complex of phosphotungstate 1 simultaneously contains hepta- and hexa-NiII-substituted trivacant Keggin units [{Ni7(μ 3-OH)3O2(dap)3(H2O) 6}(B-α-PW9O34]2- and [{Ni 6(μ3-OH)3(dap)3-(H 2O)6)(B-α-PW9O34)]. The dimeric silicotungstate 2 is built up from two trivacant Keggin [B-α-SiW9O34]10- fragments linked by an octa-CuII cluster. The main skeleton of 3 is a tetrameric cluster constructed from four tri-FeIII-substituted [Fe3 III(μ3-OH)3(B-α-PW9 O 34)]3- Keggin units linked by a central Fe4 IIO4 cubane core and four μ4-PO4 bridges. Complex 4 is an unprecedented three-dimensional extended architecture with hexagonal channels built by hexa-CuII clusters and trivacant Keggin [B-α-PW9O34]9- fragments. The common feature of 5-8 is that they contain a B-α-isomeric trivacant Keggin fragment capped by a hexa-NiII cluster, very similar to the hexa-NiII-substituted trivacant Keggin unit in 1. Magnetic measurements illustrate that 1, 2, and 5 have ferromagnetic couplings within the magnetic metal centers, whereas 3 and 4 reveal the antiferromagnetic exchange interactions within the magnetic metal centers. Moreover, the magnetic behavior of 4 and 5 have been theoretically simulated by the MAGPACK magnetic program package.
AB - The hydrothermal reactions of trivacant Keggin A-α-XW 9O34 polyoxoanions (X = PV/SiIV) with transition-metal ions (NiIICuII/FeII) in the presence of amines result in eight novel high-nuclear transition-metal- substituted polyoxotungstates [{Ni7(μ3-OH) 3O2-(dap)3(H2O)6}(B- αPW9O34)[{Ni6(μ3-OH) 3(dap)3(H2O)6}(B-α-PW 9O34)][Ni-(dap)2(H2O) 2]·4.5H2O (1), [Cu(dap)-(H2O) 3]2[{Cu8(dap)4(H2O) 2}(B-α-SiW9- O34)2] ·6H2O (2), (enH2)3H 15[{Fe1.5II -Fe12 III(μ3-OH)12(μ4-PO 4)4}(B-α-PW9-O34) 4]·ca.130H2O (3), [{Cu6(μ 3-OH)3-(en)3 (H2O) 3}(B-α-PW9O34)]·7H2O (4), [{Ni6(μ3-OH)3(en)3(H 2O)6}(B-α-PW9- O34)] ·7H2O (5), [(Ni6(μ3-OH) 3(en)2-(H2O)8}(B-α-PW 9O34)]·7H2O (6), [{(Ni 6-(μ3-OH)3(dap)2(H 2O)8}(B-α-PW9O34)]· 7H2O (7), and [{Ni6(μ3-OH) 3(en)3- (H2O)6}(B-α-SiW 9O34)][Ni0.5(en)]· 3.5 H2O (8) (en = ethylenediamine, dap = 1,2-diaminopropane). These compounds have been structurally characterized by elemental analyses, IR spectra, diffuse reflectance spectra, thermogravimatric analysis, and X-ray crystallography. The double-cluster complex of phosphotungstate 1 simultaneously contains hepta- and hexa-NiII-substituted trivacant Keggin units [{Ni7(μ 3-OH)3O2(dap)3(H2O) 6}(B-α-PW9O34]2- and [{Ni 6(μ3-OH)3(dap)3-(H 2O)6)(B-α-PW9O34)]. The dimeric silicotungstate 2 is built up from two trivacant Keggin [B-α-SiW9O34]10- fragments linked by an octa-CuII cluster. The main skeleton of 3 is a tetrameric cluster constructed from four tri-FeIII-substituted [Fe3 III(μ3-OH)3(B-α-PW9 O 34)]3- Keggin units linked by a central Fe4 IIO4 cubane core and four μ4-PO4 bridges. Complex 4 is an unprecedented three-dimensional extended architecture with hexagonal channels built by hexa-CuII clusters and trivacant Keggin [B-α-PW9O34]9- fragments. The common feature of 5-8 is that they contain a B-α-isomeric trivacant Keggin fragment capped by a hexa-NiII cluster, very similar to the hexa-NiII-substituted trivacant Keggin unit in 1. Magnetic measurements illustrate that 1, 2, and 5 have ferromagnetic couplings within the magnetic metal centers, whereas 3 and 4 reveal the antiferromagnetic exchange interactions within the magnetic metal centers. Moreover, the magnetic behavior of 4 and 5 have been theoretically simulated by the MAGPACK magnetic program package.
KW - Cluster compounds
KW - Hydrothermal synthesis
KW - Magnetic properties
KW - Polyoxometalates
KW - Transition metals
UR - http://www.scopus.com/inward/record.url?scp=38049186944&partnerID=8YFLogxK
U2 - 10.1002/chem.200701331
DO - 10.1002/chem.200701331
M3 - Article
AN - SCOPUS:38049186944
SN - 0947-6539
VL - 13
SP - 10030
EP - 10045
JO - Chemistry - A European Journal
JF - Chemistry - A European Journal
IS - 36
ER -