Synthesis and characterization of self-assembled inorganic–organic hybrid arsenotungstates

Abstract

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.

Structural Extension from 0D to 3D Pillared Heterometallic 3d-4f Polyoxometalate Hybrids

“…In recent years, 3d–4f metal-incorporated POMs have received growing attention owing to their intriguing topologies and unique physical-chemical properties derived from the interactions between the transition metals and lanthanide metals. − However, it is still a challenge to synthesize new 3d–4f heterometallic compounds by introducing 3d metals based on LnCPs. Compared with other transition metals, copper ions are more easily coordinated with nitrogen-containing ligands such as Hina ligands. − The Jahn–Teller effect from the octahedron geometry of Cu 2+ ions may overcome the steric hindrance and further lead to the formation of novel high-dimensional materials. − On the basis of the structural analysis of compound 1 , we found that all the N atoms of Hina ligands were uncoordinated and may act as potential coordination sites to bridge transition metals and thereby realize structural extensions.…”