strength of nucleophiles vs basicity

[Caitlin Dillon 3G]

What is the difference between the trend in how basic something is and how nucleophilic it is?

[haleh matinrad 1C]

To my understanding there is no direct general trend for them. Its just the fact that negatively charged species tend to be basic. It's important to remember that the strength of a nucleophile is relative to the reaction it is taking place in.

[Chem_Mod]

Typically something that is very basic, ie has concentrated, localized charge, such as a lone pair, will be nucleophilic as well. Something that is basic, but NOT nucleophilic will have a lone pair, but it will be inaccesible due to steric bulk. Imagine trying to deprotonate with hydroxide (OH-) vs. t-butoxide (CH3)3C-O-. They're both very basic, t-butoxide is very large and will have difficulties acting as a nucleophile.