A series of 12 inorganic-organic hybrid 4f-substituted arsenotungstates decorated with 3d-based complexes along with acetate bridging, viz. {[Cu2(H2O)(1,10-phen)2(μ-CH3COO)2]4[Ln2(H2O)2(μ-CH3COO)2(α-AsW11O39)2]}2- (LnIII = Pr, Nd, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb and Lu), have been synthesized. These compounds were isolated using a one-pot synthetic strategy with copper, lanthanoid, trilacunary arsenotungstate and 1,10-phenanthroline as precursors. They were characterized using various analytical techniques, such as single-crystal X-ray diffraction (SC-XRD), powder XRD (PXRD), Fourier transform IR (FT-IR) spectroscopy, UV-Vis spectroscopy and thermogravimetric analysis (TGA). In all these compounds, a dinuclear Ln2(ac)2 moiety is sandwiched between two monolacunary [AsW11O39]7- polyoxometalates (POMs), where the Ln2(ac)2 moiety is comprised of two acetate ligands in a μ-κO,O':κO fashion. Moreover, the anion is decorated by a copper-phenanthroline-acetate complex through a terminal O atom of the polyanion.