Editing Heteroatom

{{Short description|Atom which is not carbon or hydrogen}}
[[File:Pyridine.svg|thumb|right|upright=0.5|[[Pyridine]] is a [[heterocyclic compound]] and the heteroatom is nitrogen.]]

In [[chemistry]], a '''heteroatom''' ({{ety|grc|heteros|different||atomos|uncut}}) is, strictly, any [[atom]] that is not [[carbon]] or [[hydrogen]].<ref>{{cite book | title = Chemistry - An introduction to organic, inorganic and physical chemistry | last1 = Housecroft | first1 = Catherine E. | last2 = Constable | first2 = Edwin C. | year = 2006 | publisher = Prentice Hall | edition = 3rd | isbn = 978-0131275676 | page = 945}}</ref>

==Organic chemistry==
In practice, the term is mainly used more specifically to indicate that non-carbon atoms have replaced carbon in the backbone of the [[Molecular geometry|molecular structure]]. Typical heteroatoms are [[nitrogen]] (N), [[oxygen]] (O), [[sulfur]] (S), [[phosphorus]] (P), [[chlorine]] (Cl), [[bromine]] (Br), and [[iodine]] (I),<ref>{{cite journal |title=Role of the heteroatom on stereoselectivity in the complex metal hydride reduction of six-membered cyclic ketones |journal=Chirality |last=Senda |first=Y. |year=2002 |volume=14 |issue=2–3 |pages=110–120 |doi=10.1002/chir.10051|pmid=11835553}}</ref><ref>{{cite encyclopedia |last=Walling |first=Cheves |editor-last=Mayo |editor-first=Frank R. |encyclopedia=Oxidation of Organic Compounds |series=Advances in Chemistry |volume=75 |isbn=9780841200760 |doi=10.1021/ba-1968-0075.ch013 |pages=166–173 |year=1968 |chapter=The Role of Heteroatoms in Oxidation}}</ref> as well as the metals [[lithium]] (Li) and [[magnesium]] (Mg).

==Proteins==
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)|Protein Data Bank]] file format, a heteroatom record (HETATM) describes an atom as belonging to a small molecule [[Cofactor (biochemistry)|cofactor]] rather than being part of a [[biopolymer]] chain.<ref name="pdbformat">{{cite web|url=http://www.wwpdb.org/documentation/format32/v3.2.html |title=Atomic Coordinate Entry Format Version 3.2 |publisher=wwPDB |date=October 2008 |url-status=dead |archive-url=https://web.archive.org/web/20110814055416/http://www.wwpdb.org/documentation/format32/v3.2.html |archive-date=2011-08-14 }}</ref>

==Zeolites==
In the context of [[zeolite]]s, 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]].<ref>{{cite book |last1=Xu |last2=Pang |last3=Yu |last4=Huo |last5=Chen |title=Chemistry of Zeolites and Related Porous Materials: Synthesis and Structure |isbn=978-0470822333 |year=2007 |pages=373}}</ref> The goal is usually to adjust properties of the material (e.g., [[Lewis acids and bases|Lewis acidity]]) to optimize the material for a certain application (e.g., [[catalysis]]).

==References==
{{Reflist}}

==External links==
{{Wiktionary}}
* [http://onlinelibrary.wiley.com/journal/10.1002/%28ISSN%291098-1071/issues Journal - Heteroatom Chemistry]

[[Category:Organic chemistry]]