Tetravalent chemistry

Although the +3 oxidation state dominates lanthanide chemistry, other oxidation states are accessible, especially if a 4f°, 4f7 or 4f14 configuration is generated. The most common 2+ ions are Eu2+ (4f7) and Yb2+ (4f14), and the most common 4+ ions are Ce4+ (4f°) and Tb4+ (4f7). Of the five lanthanides that exhibit tetravalent chemistry, Nd4+ and Dy4+ are confined to solid-state... 

Homogeneous Catalysis Lanthanide Halides Organometallic Chemistry Fundamental Properties Tetravalent Chemisiry Inoiganic Tetravalent Chemistry Organometallic The Divalent State in Solid Rare Earth Metal Halides The Electronic Structure of the Lanthanides. 

The enthalpy of vaporization of the metals refers to the process Ln s) — LU(g). This has an influence in the stability of oxidation states of the lanthanides (see Variable Valency, The Divalent State in Solid Rare Earth Metal Halides, and Tetravalent Chemistry Inorganic) and the variation of AHvap across the series is shown in Figure 3. 

Lanthanides Coordination Chemistry Organometal-lic Chemistry Fundamental Properties Tetravalent Chemistry Inorganic Variable Valency. 

In order to fully understand the crystal chemistry of the anhydrous LnXs and their solvates ([LnXj(solv) ]), the Ln atomic properties of these species must be considered. The predominant oxidation state for LnX species is the +3 state however, for a number of these cations, tiie +2 (see The Divalent State in Solid Rare Earth Metal Halides) and +4 (see Tetravalent Chemistry Inorganic) states are available. Since the bonding in these compounds is mainly ionic, the cation size and sterics of the binding solvent play a significant role in determining the final crystal structures isolated. The ionic nature of the LnX complexes makes... 

Even flien well-characterized coordination compoimds are limited to only a few classes of compounds. Notable are, e.g., halogeno complexes and complexes of oxo acids, p-diketonates and related SchifF-base complexes, as well as porphyrinates and related complexes. Two other important classes of cerium(lV) compounds, the alkoxides and amides of Ce" +, can be regarded as pjewfifo-organometallics and are discnssed together with the organocerium(IV) complexes in Tetravalent Chemistry OrganometalUc. 

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