Hydrothermal synthesis and crystal structures of Nd(IO3)3 and AI(IO3)3

Two metal iodates, Nd(IO3)(3) and AI(IO3)(3), have been prepared by hydrothermal reactions at 170 degrees C. The X-ray single-crystal structural analysis showed that Nd(IO3)(3) presented here is a new polymorph crystallizing in a monoclinic space group P2(1)/n In with a = 8.859(1) angstrom, b = 5.9296(5)angstrom, c = 15.301(3)angstrom, beta=96.95(1)degrees, Z=4. Al(IO3)(3) crystallizes in a non-centrosymmetric group P6(3) with a=9.003(1)angstrom, c = 5.2406(5) angstrom, Z=2. The crystal structure of Nd(IO3)(3) consists of 1D chains of edge-sharing NdO9 polyhedra, which are stitched into slabs through the bridging 103 groups; and slabs are held together via the weak I-O bonds resulting in a 3D framework. AI(103)3 is characterized by the slightly distorted AlO6 octahedra that are bridged by 103 groups giving rise to a 3D polar network. Infrared spectra further confirmed that both compounds contain low symmetric IO3- groups. (c) 2005 Elsevier B.V. All rights reserved.