ironsulfurcontaining

Iron-sulfur containing compounds refer to chemical species that include iron and sulfur in their composition. They span inorganic solids, minerals, and biological cofactors, and they play important roles in geology, catalysis, and biochemistry. The term encompasses simple binary sulfides as well as complex, polynuclear clusters where iron centers participate in electron transfer reactions.

Inorganic iron sulfides include several binary compounds such as pyrite (FeS2), troilite (FeS), and mackinawite (FeS). Pyrite and marcasite are polymorphs of FeS2; pyrrhotite refers to iron-deficient iron sulfides with variable composition Fe1−xS. These minerals form under reducing conditions and are common in sedimentary rocks and hydrothermal systems. Iron sulfides often exhibit metallic luster, variable magnetism, and sensitivity to oxidation.

Biological systems employ iron-sulfur clusters as cofactors in enzymes. Common motifs include [2Fe-2S], [3Fe-4S], and [4Fe-4S] clusters, which can cycle between different oxidation states to transfer electrons. These clusters occur in ferredoxins and a wide range of oxidoreductases. They are assembled by dedicated protein machinery and are typically sensitive to oxygen and proton conditions.

Because of their redox versatility, iron-sulfur containing compounds are studied in catalysis, energy conversion, and materials science. Iron sulfide minerals can participate in catalysis and environmental chemistry, including reactions relevant to the sulfur cycle and corrosion processes. In materials science, iron-sulfur nanoparticles and clusters are explored for electronic and magnetic properties.