Three 3D organic–inorganic hybrid heterometallic polyoxotungstates assembled from 1:2-type [Ln(α-SiW11O39)2]13− silicotungstates and [Cu(dap)2]2+ linkers

Three organic–inorganic hybrid monolacunary Keggin silicotungstate-based 3d–4f heterometallic derivatives NaH[Cu(dap)2(H2O)][Cu(dap)2]4.5[Ln(α-SiW11O39)2]·7H2O (Ln = SmIII for 1, DyIII for 2, GdIII for 3) have been prepared by the hydrothermal reaction of Na10[A-α-SiW9O34]·18H2O, CuCl2·2H2O, LnCl3 and dap (dap = 1,2-diaminopropane) and characterized by elemental analyses, IR spectra and X-ray single-crystal diffraction. 1–3 display the novel 3D CuII–LnIII heterometallic frameworks with the scarce 5-connected (46·64) topology and their common features are that they all consist of 1:2-type [Ln(α-SiW11O39)2]13− subunits and [Cu(dap)2]2+ connectors. To the best of our knowledge, 1–3 represent the rare 3D organic–inorganic hybrid Keggin silicotungstate-based 3d–4f heterometallic derivatives. In addition, the photoluminescence properties of 1 and 2 have been investigated and the magnetic susceptibilities of 1–3 have been measured.