Rare Earth Iodide Complexes of 4-Formyl-2, 3-dimethyl-1-phenyl-3-pyrazolin-5-one

摘要

Rare earth complexes of 4-formyl-2, 3-dimethyl-1-phenyl-3-pyrazolin-5-one (FDPP) having the general formula[Ln(FDPP)4I2]I, where Ln= Y, La, Pr, Nd, Sm, Eu, Gd, Dy, Ho andEr, have been synthesised and characterised by elemental analyses,molar conductance in non-aqueous solvents, electronic, infraredand proton NMR spectra as well as thermogravimetric analyses.FDPP acts as a neutral monodentate ligand coordinating throughthe ring carbonyl oxygen. Two of the iodide ions are coordinated.A coordination number of six may the assigned to the metal ion inthese complexes. The covalency parameters evaluated from thesolid state electronic spectra suggest weak covalent character ofthe metal-ligand bond. The TG data of the lanthanum complexindicate that the complex is stable up to about 140℃ andundergoes decomposition in three stages forming lanthanum oxideas the final product.