Two novel 2D organic–inorganic hybrid lacunary Keggin phosphotungstate 3d–4f heterometallic derivatives: [Cu(en)2]2H6[Ce(α-PW11O39)2]·8H2O and [Cu(dap)2(H2O)][Cu(dap)2]4.5[Dy(α-PW11O39)2]·4H2O

The reaction of 2(NH4)2SO4Ce(SO4)2·2H2O or DyCl3 with CuCl2·2H2O, Na9[A-α-PW9O34]·7H2O in the presence of ethylenediamine (en) or 1,2-diaminopropane (dap) under hydrothermal conditions led to two novel 2D organic–inorganic hybrid monovacant Keggin phosphotungstate 3d–4f heterometallic derivatives [Cu(en)2]2H6 [Ce(α-PW11O39)2]·8H2O (1) and [Cu(dap)2(H2O)][Cu(dap)2]4.5[Dy(α-PW11O39)2]·4H2O (2), which were structurally characterized by elemental analyses, IR spectra, powder X-ray diffraction (PXRD) and single-crystal X-ray diffraction. 1 displays an interesting 2D 3d–4f heterometallic sheet architecture with a 4-connected topology constructed from 1:2-type [Ce(α-PW11O39)2]10– subunits and [Cu(en)2]2+ bridges whereas illustrates the other unique 2D 3d–4f heterometallic sheet with a 5-connected topology established by 1:2-type [Dy(α-PW11O39)2]11− subunits and [Cu(dap)2]2+ bridges. To the best of our knowledge, and represent scare organic–inorganic hybrid 2D 3d–4f heterometallic monovacant Keggin phosphotungstates. Moreover, the solid-state photoluminescence of 2 was investigated.