0-D and 1-D inorganic-organic composite polyoxotungstates constructed from in-situ generated monocopperII-substituted Keggin polyoxoanions and copperII-organoamine complexes

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]210- polyoxoanions via [Cu(en)2]2+ bridges in the pattern of -A-B-A-B- (A=[α-PCuW11O39]210-, 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. - Graphical abstract: A family of inorganic-organic composite polyoxotugstates have been harvested by combination of in-situ generated monocopperII-substituted Keggin polyoxoanions and copperII-organoamine complexes based on di-/tri-/hexa-vacant polyoxoanion precursors, CuCl2.2H2O and organoamines under hydrothermal conditions and structurally characterized by the elemental analysis, IR spectroscopy, TGA and single-crystal X-ray crystallography