Hafnium chemistry

For an overview of organozirconium and -hafnium chemistry, see P. C. Wailes, R. S. P. Coutts, H. Weigold, Organometallic Chemistry of Titanium, Zirconium, and Hafnium, Academic Press, New York, 1974, p. 302. D. J. Cardin, M. F. Lappeet, C. L. Raston Chemistry of Organozirconium and Hafnium Compounds, John Wiley Sons, New York, 1986, p. 451. 

A simplified series of reactions between a hafnium salt and sulfuric acid is given in Fig. 4.3. The reactions showcase important facets of thin-film synthesis (but do not address the precise identities of intermediates or complexities of aqueous hafnium chemistry.) In the first step, a hafnium oxide chloride crystal hydrate is dissolved in water to disperse small hafnium-hydroxo molecular clusters. Sulfato ligands are subsequently added in the form of sulfuric acid. Since sulfato binds more strongly than chloro, hafnium-hydroxo-sulfato aqueous species are created. Under mild heating, these species readily poly-... 

A similar hafnium chemistry has not been developed. The slower rates of reaction of hafnium compounds relative to zirconium and titanium make them less interesting as synthetic agents, though they provide an advantage in unraveling mechanistic details of these processes. 

Angew, Chem. fnt Ed. 5, 15 ( 966). Reviews of zirconium and Us compdsr W, B. Blumenthal, The Chemical Behavior of Zirconium (Van Nostrand, Princeton, 1958) Gmetin s Handb, Anorg. Chem., Zirconium (8th ed.) 42, (1958) 448 pp Larsen. Zirconium and Hafnium Chemistry in Advan. inorg, Chem. Rodiochem. 13, 1-333(1970) Bradley, Thornton, Zirconium and Hafnium" in Comprehensive Inorganic Chemistry, vol. 3, I. C. Bailar, Jr. et at.. Eds. (Pergamon Press. Oxford. 1973) pp 419-490. 

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