heteroelements

Heteroelements, in chemistry, are elements other than carbon and hydrogen that participate in the structure and chemistry of a compound. The term emphasizes the role of atoms that replace or augment the carbon-hydrogen framework, often called heteroatoms when discussing organic molecules. Heteroelements encompass a wide range of elements, including nitrogen, oxygen, sulfur, and phosphorus, as well as halogens, silicon, boron, and several transition metals in coordination chemistry.

In many compounds heteroelements introduce functional groups and determine reactivity, polarity, and acidity. Their multiple valence states and lone pairs enable diverse bonding patterns, from covalent to ionic and coordinate bonds. Common heteroatom-containing motifs include amines, alcohols, carbonyls, halides, phosphates, and sulfides. The properties of a molecule are strongly influenced by the heteroelements present.

Heteroelements are central to many fields: organic synthesis, medicinal chemistry, materials science, and catalysis. Heteroatom chemistry covers reactions such as nucleophilic substitution, oxidation/reduction, and coordination chemistry with metal centers. Heterocyclic compounds—rings that include heteroelements such as N, O, or S—are especially important in biology and drug design.