Solution and solid-state structues of lanthanide itrate complexes with[MeO)_2p(o)]_2C(OH)R(R=Me,~TBu)

摘要

The complexes Ln(NO-3)_3L_2~a(L-[(MeO)_2P(OH)]_2C(OH)Me;Ln=La-Er) and Ln(NO_3)_3L_2~b (L~b-[(MeO)_2P(O)]_2C(OH)~tBu); Ln=La-Lu)have beensynthesised.Thesolid-statestructures examined by IR spectroscopy,single crystal X-ray diffraction and extended X-ray absorption fine structure show uniformity across the series up to Dy,themetalbeing ten coordinate.Solutio structures have been examined by ~(31)P NMR spectroscopy,conductivity,electrospray mass spectrometry and EXAFS,and results indicate that solution structures fall inot two groups,one for the lighter (La-Sm) and one for the heavier(Eu-Lu) lanthanides.This structural change involves the diphosphonate ligands,whichappear to be monodenate for the heaviwer metals,affording these a coordiantion number of eight.