Inchemistry, aheteroatom (from Ancient Greek heteros 'different' and atomos 'uncut') is, strictly, anyatom that is notcarbon orhydrogen.[1]
In practice, the term is mainly used more specifically to indicate that non-carbon atoms have replaced carbon in the backbone of themolecular structure. Typical heteroatoms arenitrogen (N),oxygen (O),sulfur (S),phosphorus (P),chlorine (Cl),bromine (Br), andiodine (I),[2][3] as well as the metalslithium (Li) andmagnesium (Mg).
It can also be used with highly specific meanings in specialised contexts. In the description ofprotein structure, in particular in theProtein Data Bank file format, a heteroatom record (HETATM) describes an atom as belonging to a small moleculecofactor rather than being part of abiopolymer chain.[4]
In the context ofzeolites, the termheteroatom refers to partialisomorphous substitution of the typical framework atoms (silicon,aluminium, andphosphorus) by other elements such asberyllium,vanadium, andchromium.[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).
