oxideoxidehydroxide

Oxideoxidehydroxide is a nonstandard term used to describe compounds that incorporate both oxide and hydroxide groups in their structure. In practice, the expression often appears as a shorthand for oxyhydroxides or mixed oxide–hydroxide phases with the general formula MxOy(OH)z, where metal cations are coordinated to oxide and hydroxide anions. The term is not widely used in formal inorganic nomenclature, but it can appear in materials science discussions to emphasize the coexistence of oxide and hydroxide motifs within a single solid.

Common examples include ferric oxyhydroxides such as goethite (FeO(OH)) and lepidocrocite (γ-FeOOH), as well as aluminum oxyhydroxide boehmite (AlOOH). These materials often feature metal cations in octahedral coordination connected through hydroxide bridges, forming layered or framework structures. Dehydration at elevated temperatures can convert oxyhydroxides to oxides (for example, FeO(OH) to Fe2O3), while hydration can restore the hydroxide-containing form.

Occurrence and significance are tied to weathering processes and soil chemistry. In nature, these compounds are common products of oxidation and hydrolysis of metallic minerals, contributing to soil coloration, nutrient cycling, and contaminant adsorption. Boehmite and related oxyhydroxides also occur as components of bauxite and other ore deposits.

Properties and applications reflect the presence of surface hydroxyl groups, which impart acidity/basicity, tunable surface charge, and high adsorption capacity. These features make oxide hydroxides useful as environmental adsorbents, catalysts, and pigments. Synthesis typically involves controlled precipitation from metal salts with bases, followed by aging or hydrothermal treatment to tailor structure and water content.

Because naming conventions vary, many researchers prefer the terms oxyhydroxide or hydroxy oxide to describe these compounds rather than the condensed form "oxideoxidehydroxide."