Editing Nucleophile (section)

{{short description|Chemical species that donates an electron pair}}
[[File:Hydrox subst.png|thumb|A [[hydroxide]] ion acting as a nucleophile in an [[SN2 reaction|S<sub>N</sub>2 reaction]], converting a [[haloalkane]] into an [[Alcohol (chemistry)|alcohol]]]]
In [[chemistry]], a '''nucleophile''' is a [[chemical species]] that forms bonds by donating an [[electron pair]]. All [[molecule]]s and [[ion]]s with a free pair of electrons or at least one [[pi bond]] can act as nucleophiles. Because nucleophiles donate electrons, they are [[Lewis base]]s.

''Nucleophilic'' describes the affinity of a nucleophile to bond with positively charged [[Atomic nucleus|atomic nuclei]]. Nucleophilicity, sometimes referred to as nucleophile strength, refers to a substance's nucleophilic character and is often used to compare the affinity of [[atom]]s. Neutral nucleophilic reactions with [[solvent]]s such as [[Alcohol (chemistry)|alcohol]]s and water are named [[solvolysis]]. Nucleophiles may take part in [[nucleophilic substitution]], whereby a nucleophile becomes attracted to a full or partial positive charge, and [[nucleophilic addition]]. Nucleophilicity is closely related to [[basicity]]. The difference between the two is, that [[basicity]] is a [[thermodynamic]] property (i.e. relates to an equilibrium state), but nucleophilicity is a [[chemical kinetics|kinetic]] property, which relates to rates of certain chemical reactions.<ref>{{Cite journal |last=Uggerud |first=Einar |date=2006-01-23 |title=Nucleophilicity—Periodic Trends and Connection to Basicity |url=https://chemistry-europe.onlinelibrary.wiley.com/doi/10.1002/chem.200500639 |journal=Chemistry – A European Journal |language=en |volume=12 |issue=4 |pages=1127–1136 |doi=10.1002/chem.200500639 |issn=0947-6539|url-access=subscription }}</ref>