Complexation of trivalent lanthanide cations by D-ribose in the solid state.The crystal structure and FT-IR study of PrCl_3·#alpha#-D-ribopyranose·5 H_2O

摘要

The crystal structure of praseodymium chloride·#alpha#-D-ribopyranose pentahydrate,PrCl_3·C_5H_(10)O_5·5 H_2O,M_r=487.47,a=9.1989(8),b=8.8214(7),c=9.8233(9)A,#beta#=94.060(3)deg,V=795.2(1)A~3,Z=2,#mu#=0.71073 A and R=0.0418 for 1923 observed reflections and 172 parameters has been determined.The sugar provides three hydroxyl groups,ax-eq-ax for coordination.The Pr~(3+) ion is nine-coordinated with five Pr-O bonds from water molecules,three from hydroxyl groups and one from chloride.The OH,CO stretching vibrations and COH bending vibrations are shifted in the complex IR spectrum and the hydroxyl groups,water molecules,chloride ions form an extensive hydrogen-bond network.