Metal ion interactions with sugars. The crystal structure and FT-IR study of the NdCl 3–ribose complex

Abstract

The single-crystal structure of neodymium chloride–ribopyranose pentahydrate, NdCl 3·C 5H 10O 5·5H 2O was determined to have M r=490.80, a=9.138(11), b=8.830(10), c=9.811(11) Å, β=94.087(18)°, V=789.7(16) Å 3, P2 1, Z=2, μ=0.71073 Å and R=0.0198 for 2075 observed reflections. The ligand of the title complex was observed in a disordered state and two molecular configurations of NdCl 3·C 5H 10O 5·5H 2O were found in the single crystal as a pair of isomers. Both ligand moieties of the two molecules are ribopyranose forms, providing three hydroxyl groups in ax– eq– ax orientation for coordination. One ligand of the pair of isomers is β- d-ribopyranose in the 1 C 4 conformation, and the other is α- d-ribopyranose in the 4 C 1 conformation. The Nd 3+ ion is nine-coordinated with five NdO bonds from water molecules, three NdO bonds from hydroxyl groups of the ribopyranose and one NdCl bond from chloride ion. The hydroxyl groups, water molecules, chloride ions form an extensive hydrogen-bond network. The IR spectral CC,OH,CO and COH vibrations were observed to be shifted in the complex and the IR results are in accordance with those of X-ray spectroscopy.