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Abstract: Combination of in-situ generated monocopperII-substituted Keggin polyoxoanions with copperII–organoamine complexes under hydrothermal conditions results in seven inorganic–organic composite polyoxotungstates [Cu(en)2(H2O)]2{[Cu(en)2][α-PCuW11O39Cl]}·3H2O (1), {[Cu(en)2(H2O)][Cu(en)2]2[α-PCuW11O39Cl]}·6H2O (2), {[Cu(en)2(H2O)]2[Cu(en)2][α-XCuW11O39]}·5H2O (3/4, X=SiIV/GeIV), {[Cu(deta)(H2O)2]2[Cu(deta)(H2O)][α-XCuW11O39]}·5H2O (5/6, X=GeIV/SiIV) and [Cu(dap)2]2{[Cu(dap)2]2[Cu(dap)2][α-PCuW11O39]2} (7) (en=ethylenediamine, dap=1,2-diaminopropane and deta=diethylenetriamine). 1 is an isolated structure whereas 2 is a 1-D chain structure, but both contain [α-PCuW11O39Cl]6− polyoxoanions. 3–6 contain the 1-D linear chains made up of [α-XCuW11O39]6− polyoxoanions in the pattern of –A–A–A– (A=[α-XCuW11O39]6−), while 7 demonstrates the first 1-D zigzag chain constructed from [α-PCuW11O39]2 10− polyoxoanions via [Cu(en)2]2+ bridges in the pattern of –A–B–A–B– (A=[α-PCuW11O39]2 10−, B=[Cu(en)2]2+). The successful syntheses of 1–7 can provide some experimental evidences that di-/tri-/hexa-vacant polyoxoanions can be transformed into mono-vacant Keggin polyoxoanions under hydrothermal conditions. [Copyright &y& Elsevier]