1-D, 2-D, and 3-D Organic–Inorganic Hybrids Assembled from Keggin-type Polyoxometalates and 3d-4f Heterometals

Abstract

A series of organic–inorganic hybrid polyoxometalate derivatives {[Cu(en)2]1.5[Cu(en)(2,2′-bipy)(H2O)n]Ce[(α-PW11O39)2]}6– [(Ln, n) = (CeIII, 0) for 1, (PrIII, 1) for 2)], {[Cu(en)2]2(H2O)[Cu(en)(2,2′-bipy)]Ln[(α-HPW11O39)2]}4– [Ln = GdIII for 3, TbIII for 4, ErIII for 5] and {[Cu(en)2]1.5[Cu(en)(2,2′-bipy)]Nd[(α-H5PW11O39)2]}3– for 6 (2,2′-bipy =2,2′-bipyridine and en = ethylenediamine) have been successfully synthesized under hydrothermal conditions and further characterized by elemental analyses, inductively coupled plasma (ICP) analyses, X-ray powder diffraction (XRPD), IR spectra, UV spectra, electron paramagnetic resonance (EPR) spectra, thermogravimetric (TG) analyses, and single-crystal X-ray diffraction. The common features of 1–6 are that they all consist of sandwich-type [Ln(α-PW11O39)2]11– polyoxoanions as the fundamental building blocks and copper coordination cations as bridges. 1 and 2 show the 1-D zigzag chains, and 3–5 exhibit the unprecedented 2-D structures built by [Ln(α-PW11O39)2]11– polyoxoanions and [Cu(en)2]2+ and [Cu(en)(2,2′-bpy)]2+ cations, whereas 6 displays the scarce 3-D framework with a (46·64) topology. As expected, 1–6 contain two types of organic ligands. Furthermore, the photocatalysis properties of rhodamine-B (RhB) upon a 500 W Hg lamp irradiation in the presence of 1, 2, 3, 4, 5, or 6 have been examined. The photoluminescence property of 4 has been investigated.