Question

Can NaOH be good nucleophile?

Answer 1

Hydroxide anion can be an excellent nucleophile.

Explanation:

We know that a nucleophile is an electron pair donor. The `HO^-` anion can donate electron pairs and make a (strong) `C-O` bond.

`HO^(-)Na^(+) + RCH_2Cl rarr RCH_2OH + NaCldarr`

In non-aqueous solution, the nucleophilicity of the hydroxide is magnified with respect to its activity in water. In water, the anion is stabilized by hydrogen bonding interactions. No such stabilization is offered in whatever organic solvent is capable of getting it up. With alkyl halides, an alternative mechanism is elimination.

`RCH_2CH_2Cl + NaOH rarr RCH=CH_2 + NaCl`

Clearly the conditions and the substrate will influence whether substitution or elimination takes place. In both cases the precipitation of sodium chloride provides a thermodynamic driving force. The chemist does the experiment FIRST, and then rationalizes the results on the basis of conditions and reagents.

Would you consider alkoxide, `RO^-`, to be a good potential nucleophile?