[CrimpJiggler]

On a webpage I read this:

Soft Lewis bases are characterized by large ionic radii, intermediate electronegativity, highly polarizable and with low energy HOMOs.

and heard the term a few other places but I have no idea what it means and can't find an explanation by googling. Whats an intermediate electronegativity?

[Wald_ron]

On a webpage I read this:

Soft Lewis bases are characterized by large ionic radii, intermediate electronegativity, highly polarizable and with low energy HOMOs.

and heard the term a few other places but I have no idea what it means and can't find an explanation by googling. Whats an intermediate electronegativity?

1.5-2.5 on pauling scale
For the nonmetals only, the soft bases include everything that is on the 3p to sulfur, 4p to selenium and all of 5p

They all fall within that range.
High is flourine (4.0)
Chlorine and Oxygen(3.5)

[CrimpJiggler]

Thanks! I thought that an element with an intermediate electronegativity would be more attracted to really low electronegativity element such as lithium than to another element with an intermediate electronegativity.