Editing Hypervalent molecule (section)

==Definitions and nomenclature==
Hypervalent molecules were first formally defined by Jeremy I. Musher in 1969 as molecules having central atoms of group 15–18 in any [[valence (chemistry)|valence]] other than the lowest (i.e. 3, 2, 1, 0 for Groups 15, 16, 17, 18 respectively, based on the [[octet rule]]).<ref name=Musher>{{cite journal | title = The Chemistry of Hypervalent Molecules | journal = [[Angew. Chem. Int. Ed.]] | year = 1969 | volume = 8 | pages = 54–68 | doi = 10.1002/anie.196900541 | author1 = Musher, J.I.}}</ref>

Several specific classes of hypervalent molecules exist:
* [[Hypervalent iodine]] compounds are useful reagents in organic chemistry (e.g. [[Dess–Martin periodinane]])
* Tetra-, penta- and hexavalent phosphorus, silicon, and sulfur compounds (e.g. PCl<sub>5</sub>, PF<sub>5</sub>, SF<sub>6</sub>, [[sulfuranes]] and [[persulfuranes]])
* [[Noble gas compounds]] (ex. [[xenon tetrafluoride]], XeF<sub>4</sub>)
* Halogen polyfluorides (ex. [[chlorine pentafluoride]], ClF<sub>5</sub>)

===N-X-L notation===
N-X-L nomenclature, introduced collaboratively by the research groups of [[James Cullen Martin|Martin]], [[Anthony Joseph Arduengo III|Arduengo]], and [[Jay Kochi|Kochi]] in 1980,<ref>{{cite journal | last1 = Perkins | first1 = C. W. | author-link2 = James Cullen Martin | author-link3 = Anthony Joseph Arduengo III | author-link6 = Jay Kochi | last2 = Martin | first2 = J. C. | last3 = Arduengo | first3 = A. J. | last4 = Lau | first4 = W. | last5 = Alegria | first5 = A | last6 = Kochi | first6 = J. K. | year = 1980| title = An Electrically Neutral σ-Sulfuranyl Radical from the Homolysis of a Perester with Neighboring Sulfenyl Sulfur: 9-S-3 species | journal = J. Am. Chem. Soc. | volume =  102| issue = 26| pages =  7753–7759| doi = 10.1021/ja00546a019 | bibcode = 1980JAChS.102.7753P }}</ref> is often used to classify hypervalent compounds of main group elements, where:
* N represents the number of valence electrons
* X is the chemical symbol of the central atom
* L the number of [[ligand]]s to the central atom
Examples of N-X-L nomenclature include: 
* [[xenon difluoride|XeF<sub>2</sub>]], '''10-Xe-2'''
* [[phosphorus pentachloride|PCl<sub>5</sub>]], '''10-P-5'''
* [[sulfur hexafluoride|SF<sub>6</sub>]], '''12-S-6'''
* [[iodine heptafluoride|IF<sub>7</sub>]], '''14-I-7'''