ELECTRONIC STRUCTURE AND BOND CHARACTER OF COMPLEXES OF RARE EARTH CHLORIDES WITH CROWN ETHERS

A series of lanthanide complexes LnCl_3·L(Ln=La,Pr,Nd;L=15-C-5 or 18-C-6)have beensynthesized and their molecular configuration,electronic structure and bond character have been studied byXPS and quantum chemical calculation.The calculated results are in good agreement with that obtained inthe experiments.Three Cl atoms are on the same side of Ln in LnCl_3·15-C-5 and the crown ring on theother side.forming a complex molecule with coordination number 8.LnCl_3·15-C-5 is easily hygroscopic inair because of its unsaturated coordination,which differs sharply from the stable Ln(NO_3)_3·15-C-5 com-plex of coordination number 11.The HOMO and neighboring occupied MOs are composed of Cl 3p and O2p,and the LUMO and neighboring unoccupied MOs are composed of Ln orbitals.The level structure easily pro-duces Ln3d satellite in XPS caused by L→Ln charge transfer transition.Due to the coordination,the absolutevalues of the charge are decreased at Ln and O atoms,but increased at Cl atoms,which is in agreement withXPS results.