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Combination of Lacunary Polyoxometalates and High‐Nuclear Transition Metal Clusters under Hydrothermal Conditions: IX. A Series of Novel Polyoxotungstates Sandwiched by Octa‐Copper Clusters
Author(s) -
Zhao JunWei,
Wang ChunMei,
Zhang Jie,
Zheng ShouTian,
Yang GuoYu
Publication year - 2008
Publication title -
chemistry – a european journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.687
H-Index - 242
eISSN - 1521-3765
pISSN - 0947-6539
DOI - 10.1002/chem.200800856
Subject(s) - chemistry , hydrothermal circulation , lacunary function , ethylenediamine , transition metal , metal , crystallography , polyoxometalate , copper , hydrothermal synthesis , stereochemistry , nuclear chemistry , inorganic chemistry , catalysis , organic chemistry , mathematics , seismology , pure mathematics , geology
The reaction of CuCl 2 ⋅ 2 H 2 O with trivacant Keggin polyoxoanions K 8 Na 2 [A‐α‐GeW 9 O 34 ] ⋅ 25 H 2 O or K 10 [A‐ α‐SiW 9 O 34 ] ⋅ 25 H 2 O in the presence of 1,2‐diaminopropane (dap), ethylenediamine (en) or 2,2′‐bipyridine (2,2′‐bpy) under hydrothermal conditions afforded five novel hybrid inorganic–organic octa‐Cu sandwiched polyoxotungstates (POTs): H 4 [Cu II 8 (dap) 4 (H 2 O) 2 (B‐α‐GeW 9 O 34 ) 2 ] ⋅ 13 H 2 O ( 1 ), (H 2 en) 2 [Cu II 8 (en) 4 (H 2 O) 2 (B‐α‐GeW 9 O 34 ) 2 ] ⋅ 5 H 2 O( 2 ), (H 2 en) 2 [Cu II 8 (en) 4 (H 2 O) 2 (B‐α‐SiW 9 O 34 ) 2 ] ⋅ 8 H 2 O ( 3 ), [Cu II (H 2 O) 2 ]H 2 [Cu II 8 (en) 4 (H 2 O) 2 (B‐α‐SiW 9 O 34 ) 2 ] ( 4 ), and [Cu II 2 (H 2 O) 2 (2,2′‐bpy) 2 ]{[Cu II (bdyl)] 2 [Cu II 8 (2,2′‐bpy) 4 (H 2 O) 2 (B‐α‐GeW 9 O 34 ) 2 ]} ⋅ 4 H 2 O (bdyl=2,2′‐bipyridinyl)( 5 ). Additionally, CuCl 2 ⋅ 2 H 2 O reacts with the mixture of GeO 2 , Na 2 WO 4 ⋅ 2 H 2 O, H 2 SiW 12 O 40 ⋅ 2 H 2 O in the presence of 2,2′‐bpy and 4,4′‐bpy under hydrothermal conditions leading to another novel mixed‐valent octa‐Cu sandwiched POT hybrid: [Cu I (2,2′‐bpy)(4,4′‐bpy)] 2 [{Cu I 2 (2,2′‐bpy) 2 (4,4′‐bpy)] 2 [Cu I 2 Cu II 6 (2,2′‐bpy) 2 (4,4′‐bpy) 2 (B‐α‐GeW 9 O 34 ) 2 }] ⋅ 2 H 2 O ( 6 ). 1 , 2 , and 3 are discrete dimers constructed from two trivacant Keggin [B‐α‐XW 9 O 34 ] 10− (X=Ge IV /Si IV ) fragments and an octa‐Cu cluster whereas 4 displays the 3D (3,6)‐connected nets with (4 ⋅ 6 2 )(4 2 ⋅ 6 4 ⋅ 8 7 ⋅ 10 2 ) topology, which are built by octa‐Cu sandwiched polyoxometalate building blocks through copper cation bridges. 5 is a novel 2D layer based on octa‐Cu sandwiched POT clusters and [Cu II 2 (bdyl)] units. Interestingly, the rollover metalation of 2,2′‐bpy is firstly observed in the system containing the copper complex under hydrothermal conditions. 6 is a discrete mixed‐valent octa‐Cu sandwiched POT supported by two Cu I ‐complexes [Cu I 2 (2,2′‐bpy) 2 (4,4′‐bpy)] 2+ through 4,4′‐bpy bridges, which constructs a novel dodeca‐copper cluster. Notably, the octa‐Cu cluster in 6 is mixed‐valent and is different from those in 1 – 5 . To our knowledge, 1 – 6 represent a rare family of POTs incorporating novel octa‐nuclear transition‐metal clusters in polyoxometalate chemistry. They were structurally characterized by FT‐IR spectra, elemental analysis, thermogravimetric analysis, and single‐crystal X‐ray diffraction. The magnetic properties of 1 , 4 , and 5 were quantitatively analyzed by the MAGPACK software package.