Editing Ethylene (section)

==Structure and properties==
[[Image:Dewar-Chatt-Duncanson model.png|thumb|260 px|left|Orbital description of bonding between ethylene and a transition metal]]
This [[hydrocarbon]] has four [[hydrogen]] [[atom]]s bound to a pair of [[carbon]] atoms that are connected by a [[double bond]]. All six atoms that comprise ethylene are [[coplanar]]. The H-C-H [[angle]] is 117.4°, close to the 120° for ideal sp² [[hybridization (chemistry)|hybridized]] carbon. The molecule is also relatively weak: rotation about the C-C bond is a very low energy process that requires breaking the [[Pi bond|π-bond]] by supplying heat at 50&nbsp;°C.{{Citation needed|date=January 2021}}

The [[Pi bond|π-bond]] in the ethylene molecule is responsible for its useful reactivity. The double bond is a region of high [[electron density]], thus it is susceptible to attack by [[electrophiles]]. Many reactions of ethylene are catalyzed by transition metals, which bind transiently to the ethylene using both the π and π* orbitals.{{Citation needed|date=January 2021}}

Being a simple molecule, ethylene is spectroscopically simple. Its UV-vis [[Spectroscopy|spectrum]] is still used as a test of theoretical methods.<ref name=NIST_Webbook>{{cite web |title=Ethylene:UV/Visible Spectrum |work=NIST Webbook |url=http://webbook.nist.gov/cgi/cbook.cgi?ID=C74851&Units=SI&Mask=400#UV-Vis-Spec |access-date=2006-09-27 |archive-date=2017-01-19 |archive-url=https://web.archive.org/web/20170119013204/http://webbook.nist.gov/cgi/cbook.cgi?ID=C74851&Units=SI&Mask=400#UV-Vis-Spec |url-status=live }}</ref>