2-D and 3-D organic-inorganic hybrid lanthanide molybdates linking by pyridine-2,5-dicarboxylate

Seven organic-inorganic hybrid lanthanide dimolybdates [Ln(H2O)(6)Mo2O6(Hpydc)(pydc)]center dot nH(2)O (n = 0: Ln = La-III (1), Ce-III (2), Pr-III (3), Nd-III (4), Sm-III (5); n = 0.5: Ln = Eu-III (6)), and Na0.5H0.5[Er(H2O)(5)Mo2O6(pydc)(2)]center dot 3H(2)O (7) (H(2)pydc = pyridine-2,5-dicarboxylic acid) have been hydrothermally prepared and further characterized by elemental analyses, X-ray powder diffraction (XRPD), IR spectra, thermogravimetric (TG) analyses, and single-crystal X-ray diffraction. The common feature of 1-7 is that they all consist of Ln(III) cations and Mo-IV centers connected by oxygen atoms and H(2)pydc ligands. 1-6 show unprecedented 3D 8-connected networks with the Schlafli symbol of (3(4).4(17).5(4).6(3)), while 7 exhibits the 2D 4-connected (4(5).6) structure. Furthermore, the luminescence properties of 5 and 6 are derived from the combination of Ln cations and H(2)pydc ligands, whereas 1-4 and 7 are attributable to H(2)pydc ligands.