protóxidos

Protóxidos are a class of chemical compounds that represent an intermediate oxidation state between a pure metal and its higher-valent oxides. The term originates from the Greek words *proto*, meaning "first" or "primary," and *oxide*, referring to compounds containing oxygen combined with another element. Unlike traditional oxides, which typically exhibit higher oxidation states, protóxidos often feature metals in lower oxidation states, often +1 or +2, and are generally less stable or less common.

These compounds are frequently encountered in transition metals, particularly those in groups 3 through 12 of the periodic table. For example, copper(I) oxide (Cu₂O) is a well-known protóxido, where copper exists in the +1 oxidation state rather than the more common +2 state seen in copper(II) oxide (CuO). Protóxidos often exhibit distinct physical and chemical properties compared to their higher-valent counterparts, such as different colors, solubilities, and reactivities.

In some cases, protóxidos can act as precursors to more stable oxides or other metal compounds. They may also play roles in catalytic processes or as intermediates in industrial synthesis. However, their relative instability or rarity limits their widespread industrial applications compared to more common oxides. The study of protóxidos contributes to understanding redox chemistry and the behavior of metals in varying oxidation states.

While the term *protóxido* is not universally standardized, it is sometimes used interchangeably with *lower oxides* or *suboxides* in scientific literature. The distinction between protóxidos and higher-valent oxides is particularly relevant in fields like materials science, electrochemistry, and inorganic chemistry, where oxidation state influences material properties and reactivity.