A nucleofuge is a leaving group which retains the lone pair from its previous bond with another species. For example, in the S_N2 mechanism a nucleophile attacks an organic compound containing the nucleofuge (the bromo group) which simultaneously breaks the bond with the nucleofuge. A leaving group is an atom or molecule that detaches from an organic molecule, which, after detachment, is called the residual or main part. ... The SN2 reaction is a type of nucleophilic substitution, where a nucleophile attacks an electrophilic center and bonds to it, expelling another group called a leaving group. ... In chemistry, a nucleophile (literally nucleus lover) is a reagent which is attracted to centres of positive charge. ... General Name, Symbol, Number bromine, Br, 35 Series halogens Group, Period, Block 17 (VIIA), 4, p Density, Hardness 3119 kg/m3 (300 K), NA Appearance Gas: red-brown solid: metallic luster Atomic properties Atomic weight 79. ... In organic chemistry, functional groups are specific groups of atoms within molecules, that are responsible for the characteristic chemical reactions of those molecules. ...

After a reaction nucleofuges may contain either a negative or a neutral charge; this is governed by the nature of the specific reaction.

The word 'nucleofuge' is commonly found in older literature, but its use has been discontinued in current literature.

See also

• Electrofuge
• Nucleophile
• Electrophile