Organoscandium compound

Organoscandium chemistry is the chemistry of organometallic compounds containing a carbon to scandium chemical bond. The interest in organoscandium compounds is mostly academic but several compound classes find practical application in catalysis, especially in polymerization. A common precursor is scandium chloride.

As with the other elements in group 3 – e.g. yttrium, forming organoyttrium compounds – and the lanthanides, the dominant oxidation state for scandium in organometallic compounds is +3 (electron configuration [Ar] 3d¹4s²). The members of this group also have large ionic radii with vacant s,p and d orbitals (88 pm for Sc³⁺ compared to 67 pm for Al³⁺ ) and as a result they behave as hard Lewis acids and tend to have high coordination numbers of 9 to 12. The metal to ligand chemical bond is largely ionic.

The majority of organoscandium compounds have at least one cyclopentadienyl (Cp) ligand. The dominant species are CpScX₂, Cp₂ScX and Cp₃Sc. The mononuclear compounds are of limited utility because of poor steric shielding which makes them prone to nucleophilic addition and solvent attack.

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