Why is it that fluoride is more nucleophilic than iodide in an aprotic solvent? The Clayden textbook suggests that lower-row elements of the periodic table are more nucleophilic since their valence electrons are in higher energy levels and are therefore more reactive. However according to the slides from my lecture class, the order of nucleophilicity for halides in an aprotic solvent goes from F- > Cl- > Br- > I- which is opposite from what is stated in the Clayden textbook. Can someone please explain this?
Thank you