# Nucleophilicity of halides in solvents [duplicate]

I have studied that as electronegativity increases nucleophilicity decreases. But in the aprotic solvent the order of nucleophilicty is: $$\ce{F- > Cl- > Br- > I-}$$ but how is this possible as $\ce{F-}$ is strongly electronegative as well as a strong nucleophile Isn't this contradictory? There is no effect of the aprotic solvent on anions.

Information given : This causes the most confusion, because it is solvent-dependent. In polar protic solvents (e.g. water and alcohols, any solvent with OH) nucleophilicity increases as you go down the periodic table (F- < Cl- < Br- < I – ). In polar aprotic solvents (e.g. DMSO, acetone) the order is reversed, and the most basic nucleophiles are also the most nucleophilic. (F- > Cl – > Br – > I – ).

I want to know why my concept is wrong.

• Just to make sure I understand: did you just claim that iodide is not the best nucleophile in that series? – Zhe May 11 '18 at 13:04
• @Zhe yes I am claiming that in aprotic solvent . – INter May 11 '18 at 14:41
• Where did you see the information suggesting this trend? This is counter to my understanding, and I'm guessing it is counter to many others' understanding here based on Zhe's response. – SendersReagent May 11 '18 at 15:13
• – INter May 11 '18 at 16:17
• – INter May 11 '18 at 16:17