[McKay (OP)]

I am interested in how a anti-proton (negative) would interact with a positive "normal" matter ion. Obviously, they would attract each other, but what would happen when they come close enough to "touch"?
Would the negative electrons from whats left in the outer shell of the ion repel the negative anti-proton? (Neutral same matter class atoms repel each other when get close enough because then the outer electrons are closer than the cores). Electrons wont really annihilate with anti-protons as it would require very high velocity to push them together, right?
Or would the anti-proton smash trough the electron shell and annihilate with the core?
Or something else would happen?

[UltimateTheory]

If we will send beam of muons-, pions- to nucleus, typically hydrogen,
antiprotons to helium-4,
negative particle might replace one of electrons on orbit,
and start spinning around nucleus for some time,

In anti-proton- helium-4 case (Antiprotonic helium), it's then annihilating with part of nucleus after some time.
http://en.wikipedia.org/wiki/Muonic_atom
http://en.wikipedia.org/wiki/Antiprotonic_helium

[evan_au]

Mixing anti-protons with Helium gas is an experiment routinely done at CERN. The antiproton lasts an average of 10 microseconds before it annihilates with the nucleus. Apparently, mixing antiprotons with other substances only lasts for picoseconds before the antiproton annihilates with the nucleus.

See the links posted by Ultimate Theory.