Highest bonding states possible?

[SamBridge]

Conventionally in elementary chemistry, you really only deal with at most quadruple bonds which typically occur in the carbon group, but I know there are higher bonding states

http://en.wikipedia.org/wiki/Sextuple_bond

But, what exactly allows this to happen and what creates this limit for other atoms? Let's say you stripped all the electrons from Neon and had just the nuclei, the orbitals would fill according to whatever s2p4... pattern they have in such a way that each orbital would have a net spin of 0, an up by 1/2 and a down by 1/2. However, let's say this nuclei came into contact with another neon atom with 10 electrons, could you then have a dectupple covalent bond? Or, what else would happen?

Edited May 23, 2013 by SamBridge

[Enthalpy]

If you put two neon nuclei really close to an other (but managed to keep their electrons!), the 20 electrons would see the equivalent of a calcium nucleus and arrange themselves accordingly, that is 1s².2s².2p⁶.3s².3p⁶.4s². The binding energy of these electrons is 1786MJ/mol or 18,5keV while the narrowing energy of the pair of neon nuclei is >21MeV (inferred from >200MeV for uranium, more charged but bigger). So electrons can't keep nuclei that close, only the strong interaction can (and muons to some extent).

http://www.webelements.com/neon/atoms.html

http://www.webelements.com/calcium/atoms.html

 

Then if the nuclei were close but not that much, atomic orbitals would interfere to create bonding and antibonding molecular orbitals. If the number of protons hence electrons just fills the bonding orbitals as in N₂, you get a very stable molecule and an inert gas. Have few electrons more like in O₂, then some must go to anti-bonding orbitals. These "anti-bonding" molecular orbitals are still more favourable to the electrons than far from the charged nucleus, but less than the atomic orbitals of the separated atoms. O₂ is stable but very reactive.

http://en.wikipedia.org/wiki/Antibonding

http://en.wikipedia.org/wiki/Triplet_oxygen

 

Neon is a simple nobe gas where two sets of 2p⁶ electrons would fill three bonding and three antibonding molecular orbitals resulting from 2p, the result being less favourable to the electrons than the separated neon atoms. Same for 2s and 1s electrons, if getting even closer. Though, Ar, Kr, Xe can form "excimers" as atom pairs (or with Cl and F) which are stable for minutes and are used in UV lasers and now UV lamps.

 

I imagine excimers could build under high pressure in sonoluminescence and explain the non-thermal radiation - provided this one is real, which is difficult to observe and is debated. Pressure would in fact compact more than two nuclei, for instance in a star, so the electrons would be shared among many nuclei, resulting in a pasma or a metal (cold hydrogen does). The resulting electron energies are strongly anti-bonding and this prevents matter from collapsing, in our usual matter as well as in white dwarves, up to a limit of electron density where electron capture by protons gets more probable than beta emission, resulting in a neutron star.

[SamBridge]

Well what about the scenario I proposed? To increase the # of electrons lets just use Argon or Krypton. I have a Krypton nuclei with 0 electrons, and another with all of it's electrons. Could I get more than six covalent bonds from that?