Tetravalent chemistry alkoxides

Homogeneous Catalysis Lanthanides Coordination Chemistry Lanthanide Alkoxides Lanthanides Coordination Chemistry Tetravalent Chemistry Inorganic The Electronic Structure of the Lanthanides. 

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. 

Siloxide ligands are able to coordinate to rare earth metals in various oxidation states and coordination numbers to primarily form mono- and dinuclear complexes. In particular, the synthetic and stmctural chemistry of trivalent rare earth siloxides are well documented in the literature and show analogies with rare earth alkoxides. It is fair to state, however, that the field of divalent and tetravalent rare earth siloxides is poorly developed and that applications pertaining to the design of siloxide-based homogeneous and heterogeneous rare earth metal catalysts as well as the development of novel silicate-based materials are scarce. Although the few results of the catalytic activity of some of the rare earth siloxides in olefin... 

The sol-gel chemistry of Zr02 is similar to other tetravalent metal compounds such as Si02 and Ti02 Precursors such as zirconium halides and alkoxides are largely available, and they all hydrolyze rapidly in the presence of water. Zirconium oxide (and especially yttrium-stabilized Zr02 (YSZ)) is widely used as a thermal barrier but also as an ionic conductor (electroceramic). Even if it is not widely used for gas detection, its ionic conductivity makes it attractive as a sensor to control the oxygen level and thus the air/luel ratio in internal combustion engines. 

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