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Grade 12Organic Chemistry

Please explain !!!Why R-O^(-) [alkoxide ion] is a good nucleophile than OH^(-) [ hydroxide ion].

Profile image of Harish
8 Years agoGrade 12
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1 Answer

Profile image of Arun
8 Years ago
Alkoxides tend to be stronger bases than the hydroxide ion. Adjacent atoms in an alkane chain will donate electron density to oxygen, allowing it to be more polarizable. An increase in polarizability will allow oxygen to more easily donate electrons.The oxygen in a hydroxide ion does not experience the inductive effect. Therefore its valence electrons do not "reach" out as far.Methoxide is a relatively unhindered base, as is hydroxide. But as explained above, methoxide experiences induction whereas hydroxide does not. So one would expect methoxide to be a better nucleophile than hydroxide because it is a stronger base than hydroxide and still remains unhindered.