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.     

Molecular Design and Electronic Structure of Polynuclear Rare Earth Complexes and Clusters

Studies on the electronic structure,molecular design,syntheses of some novel series of tetranuclear rareearth complexes in our laboratory have been reviewed.Spin-unrestricted localized INDO method was used tocalculate the electronic structure and the chemical bonding in the typical rare earth cluster Sc[Sc_6Cl_(12)Co]wasdiscussed.     

Electronic Structure and Chemical Bonding of a Tetranuclear Neodymium Complex Nd_4O(OR)_4(NR''''_2)_6

The nonrelativistic DV-X_α-SCC method was used to study the electronic structure and chemi-cal bonding of tetranuclear neodymium complex Nd_4O(OR)_4(NR′_2)_6,with emphasis on the bonding charac-ter of the central μ_4-O atom and the four Nd atoms.The results of calculation show that the μ_4-O atom usesits sp~3 valence orbitals to contribute four O-Nd bonding MOs with character of multicenter bond apparent-ly.The Mulliken population analysis shows that the overlap population between Nd atoms is almost equal tozero,therefore there is no direct metal-metal bond between Nd atoms.The coordination number of Nd in thecomplex is discussed briefly.     

Study on Band Structure of YbB6 and Analysis of Its Optical Conductivity Spectrum

The electronic structure of YbB6 crystal was studied by means of density functional （GGA ＋ U） method. The calculations were performed by FLAPW method. The high accurate band structure was achieved. The correlation between the feature of the band structure and the Yb-B6 bonding in YbB6 was analyzed. On this basis, some optical constants of YbB6 such as reflectivity, dielectric function, optical conductivity, and energy-loss function were calculated. The results are in good agreement with the experiments. The real part of the optical conductivity spectrum and the energy-loss function spectrum were analyzed in detail. The assignments of the spectra were carried out to correlate the spectral peaks with the interband electronic transitions, which justify the reasonable part of previous empirical assignments and renew the missed or incorrect ones.