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    Scandium(III) and yttrium(III)
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    Abstract:
    Abstract According to the inorganic chemistry text book written by Cotton and Wilkinson, scandium is not truly a rare earth element but yttrium and lanthanides are rare earth elements. The stable oxidation state of scandium is trivalent and the ionic radius of scandium (III) is significantly smaller (0.89 Å) than those for any of the rare earth elements (1.0-1.17 Å). Chemical behaviour is intermediate between aluminium and that of lanthanides. Yttrium has a trivalent oxidation state similar to scandium and lanthanide elements and the ionic radius of yttrium (III) (1.04 Å) is close to those of erbium (1.03 A) and holmium (1.04
    Keywords:
    Scandium
    Ionic radius
    Holmium
    Rare-earth element
    Oxidation state
    Lanthanum
    Cocondensation of scandium vapour with 1,3,5-tri-tert-butylbenzene affords the first example of a scandium(0) complex, the sandwich compound bis(η-1,3,5-tri-tert-butylbenzene)scandium; ESR and UV studies also the reveal the presence of a second compound from this reaction, formulated as a similarly unique example of scandium(II) arising from activation of one of the methyl groups of a tert-butyl ring substituent.
    Scandium
    Citations (53)
    Scandium
    Oxidation state
    Zero (linguistics)
    Citations (187)
    Scandium is probably the least-studied element in the fourth period. It is commonly grouped with yttrium and the lanthanides in Group 3 (IIIA), yet its atom (and ion) are considerably smaller than those of yttrium and lanthanum; it is however larger than Al3+ (with which it is often compared; ionic radius 0.5 Å in Group 13 (IIIB)). Table 1.1 compares the coordination numbers of scandium and lanthanides in a selection of coordination compounds with those of iron(III), a d5 ion with no ligand-field effects dictating the adoption of a particular coordination number.
    Scandium
    Ionic radius
    Lanthanum
    Coordination number
    Abstract In this work, the effects of scandium introduction on the luminescence of yttrium scandium (Sc) aluminium garnet powders doped with ytterbium (YSAG: Yb 3+ ) were investigated. Based on photoluminescence (PL) and photoluminescence excitation (PLE) spectra we made conclusions about the influence of scandium concentration and location on emission properties of ytterbium ions in YSAG. On the one hand, an analysis of the data showed that the increase of Sc concentration leads to broadening spectral lines regardless of a location of scandium ions in the crystal structure. On the other hand, the photoluminescence intensity of ytterbium ions in YSAG is more sensitive to scandium in the octahedral site than to scandium in the dodecahedral site.
    Scandium
    Ytterbium
    Photoluminescence excitation
    Through extensive molecular modelling of Fe(III/IV)-oxo and Fe(III)-hydroxo complexes it is shown here unambiguously that the assignment of the iron oxidation state of a Sc(3+)-capped iron-oxygen species should be revised. Iron in this Lewis-acid capped metal-bound oxygen system is Fe(III), coinciding with water as a secondary axial ligand to scandium.
    Scandium
    Oxidation state
    Molecular oxygen
    Citations (77)