Gadolinium: Central Metal of the Lanthanoids

• Autores: Michael Laing
• Localización: Journal of chemical education, ISSN 0021-9584, Vol. 86, Nº. 2 (February), 2009, págs. 188-189
• Idioma: inglés
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• Resumen

  • The physical and chemical properties of gadolinium are compared with those of the other lanthanoids. Some properties are intermediate between those of lanthanum and lutetium; some between those of barium and hafnium; and others (unexpectedly) between those of ytterbium and lutetium. Both the remarkably high molar heat capacity of the metal and the discontinuous expansion of its unit cell parameters on cooling are related to its unusual magnetic properties. The gadolinium break is a real discontinuity observed in many properties: ionic radii, formation constants of complexes, and solvent extraction equilibria. The sawtooth pattern of values of IE3 and ΔHat with atomic number for the lanthanoids is related to the quantum number L of the atomic species. The regular crystal field approach does not apply to the lanthanoid cations. A new arrangement of the lanthanoids in the periodic table places La, Gd, Lu in a column below Y, all having valence electron configuration s2d1.