Pyridine is a heterocyclic compound and the heteroatom is nitrogen.
Pyridine is a heterocyclic compound and the heteroatom is nitrogen.

In chemistry, a heteroatom (from Ancient Greek heteros 'different', and atomos 'uncut') is, strictly, any atom that is not carbon or hydrogen.[1]

Organic chemistry

In practice, the term is usually used more specifically to indicate that non-carbon atoms have replaced carbon in the backbone of the molecular structure. Typical heteroatoms are nitrogen (N), oxygen (O), sulfur (S), phosphorus (P), chlorine (Cl), bromine (Br), and iodine (I),[2][3] as well as the metals lithium (Li) and magnesium (Mg).


It can also be used with highly specific meanings in specialised contexts. In the description of protein structure, in particular in the Protein Data Bank file format, a heteroatom record (HETATM) describes an atom as belonging to a small molecule cofactor rather than being part of a biopolymer chain.[4]


In the context of zeolites, the term heteroatom refers to partial isomorphous substitution of the typical framework atoms (silicon, aluminium, and phosphorus) by other elements such as beryllium, vanadium, and chromium.[5] The goal is usually to adjust properties of the material (e.g., Lewis acidity) to optimize the material for a certain application (e.g., catalysis).


  1. ^ Housecroft, Catherine E.; Constable, Edwin C. (2006). Chemistry - An introduction to organic, inorganic and physical chemistry (3rd ed.). Prentice Hall. p. 945. ISBN 978-0131275676.
  2. ^ Senda, Y. (2002). "Role of the heteroatom on stereoselectivity in the complex metal hydride reduction of six-membered cyclic ketones". Chirality. 14 (2–3): 110–120. doi:10.1002/chir.10051. PMID 11835553.
  3. ^ Walling, Cheves (1968). "The Role of Heteroatoms in Oxidation". In Mayo, Frank R. (ed.). Oxidation of Organic Compounds. Advances in Chemistry. Vol. 75. pp. 166–173. doi:10.1021/ba-1968-0075.ch013. ISBN 9780841200760.
  4. ^ "Atomic Coordinate Entry Format Version 3.2". wwPDB. October 2008. Archived from the original on 2011-08-14.
  5. ^ Xu; Pang; Yu; Huo; Chen (2007). Chemistry of Zeolites and Related Porous Materials: Synthesis and Structure. p. 373. ISBN 978-0470822333.