[strigoi]

Im writing about proton sponges, and i'd like to include N,N-dimethyl aniline basicity to compare with that of protons sponges.

However, the pKa in water for N,N-dimethyl aniline i keep finding is around 5.1. Yet it is also referred as weakly basic. How does this pKa value make it basic? Shouldnt it be more acidic than basic?

Im kinda trying to compare how adding 2 weakly basic compounds (N,N-dimethyl aniline) together can form superbase (proton sponge, DMAN). Just feels stupid to say this, if N,N-dimethyl aniline isnt even basic to begin with.

[strigoi]

EDIT: Kept saying amine, meant N,N dimethyl aniline

[Babcock_Hall]

The pK_a of acetic acid is about 5, and I would say that its conjugate base, acetate, is a weak base.  With respect to dimethyl aniline versus proton sponges, I would try drawing each conjugate acid out next to each other and look for differences.
EDT
I second mjc123's point.  I find it helpful to specify the exact conjugate acid when dealing with nitrogen compounds.  I also added the phrase "conjugate acid" to a portion of my comment above.  The proton sponges have generated some interest in physical organic chemistry.

[mjc123]

The quoted pKa is for the conjugate acid of DMA. N,N-DMA has no protons that would normally be considered "acidic".

[strigoi]

Thanks guys! This helped, almost done with the essay.