Lanthanum ionization energy

He(I) photoelectron spectra of lanthanum tris-yS -diketonate complexes have been studied and the spectra interpreted on the basis of quantum chemical calculations of ground and ionized states by X -DV and ab initio methods [54]. The comparative analysis of the photoelectron spectra of Sc, and Lu tris-acetylacetonates showed that substitution of one oxygen atom by NH group shifts the two pairs of n and n orbitals to a different extent. The IE (ionization energy) values for (e) and 7T3 (ai) orbitals decreased by 0.8-1.0 eV. The n and n+ molecular orbital two pair bands showed a weak shift of 0.1 eV or less. 

Question 2.3 Assuming lattice energies for CeFs and Cep4 of —4915 and —8391 kJ/mol respectively, and using the same enthalpy of atomization and electron affinity for fluorine as in the lanthanum examples (Section 2.9.1.), calculate A7/f for Cep3 and Cep4. Take an enthalpy of atomization of 398 kJ/mol for cerium (Table 2.6). Use ionization energies from Table 2.2. 

Laboratory reagents, preparation of, 8-1 to 4 Laboratory Solvents and Other Liquid Reagents, 15-13 to 22 Laguerre polynomials, A-83 to 85 Lanthanum see also Elements electrical resistivity, 12-39 to 40 electron configuration, 1-18 to 19 heat capacity, 4-135 history, occurrence, uses, 4-1 to 42 ionization energy, 10-203 to 205 isotopes and their properties, 11-56 to 253 magnetic susceptibility, 4-142 to 147 molten, density, 4-139 to 141 physical properties, 4-133 to 134 thermal properties, 12-201 to 202 vapor pressure, 6-61 to 90 vapor pressure, high temperature, 4-136 to 137... 

The rare earth (RE) ions most commonly used for applications as phosphors, lasers, and amplifiers are the so-called lanthanide ions. Lanthanide ions are formed by ionization of a nnmber of atoms located in periodic table after lanthanum from the cerium atom (atomic number 58), which has an onter electronic configuration 5s 5p 5d 4f 6s, to the ytterbium atom (atomic number 70), with an outer electronic configuration 5s 5p 4f " 6s. These atoms are nsnally incorporated in crystals as divalent or trivalent cations. In trivalent ions 5d, 6s, and some 4f electrons are removed and so (RE) + ions deal with transitions between electronic energy sublevels of the 4f" electroiuc configuration. Divalent lanthanide ions contain one more f electron (for instance, the Eu + ion has the same electronic configuration as the Gd + ion, the next element in the periodic table) but, at variance with trivalent ions, they tand use to show f d interconfigurational optical transitions. This aspect leads to quite different spectroscopic properties between divalent and trivalent ions, and so we will discuss them separately. 

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