Metal-ion interactions with sugars. Crystal structure and FT-IR study of PrCl3-D-ribose complex.
A single-crystal of PrCl3.D-ribose.5H2O was obtained from a methanol-water solution and its structure determined by X-ray crystallography. Two configurations of the complex, as a pair of isomers, were found in the single-crystal in a disordered state, which differs from that reported previously. The ligand of one of the complexes is alpha-D-ribopyranose in the 4C1 conformation, and the ligand of the other is beta-D-ribopyranose in the 1C4 conformation. The alpha:beta anomeric ratio is 54:46. Both ligands of the two isomers provide three hydroxyl groups in an axial-equatorial-axial orientation for coordination. The Pr3+ ion is nine-coordinated, with five Pr-O bonds from water molecules, three Pr-O bonds from the hydroxyl groups of the D-ribopyranose and one Pr-Cl bond from chloride ion. The hydroxyl groups, water molecules, and chloride ions form an extensive hydrogen-bond network. The IR spectral C-C, O-H, C-O, and C-O-H vibrations are shifted in the complex, compared to those in d-ribose, and the IR results are in accord with those obtained from the X-ray diffraction study.
Lu
Yan
Y
Department of Chemical Engineering, Shanghai Institute of Technology, Shanghai 200235, China. luuyann@vip.sina.com
Guo
Jianyu
J
D018360:Crystallography, X-Ray; D007477:Ions / Q000737:chemistry; D008670:Metals / Q000737:chemistry*; D015394:Molecular Structure; D011221:Praseodymium / Q000737:chemistry*; D012266:Ribose / Q000737:chemistry*; D017550:Spectroscopy, Fourier Transform Infrared
D007477:Ions; D008670:Metals; D012266:Ribose; D011221:Praseodymium