Sciencemadness Discussion Board

Salts of protonated hydrogen.

Pyrovus - 27-8-2006 at 03:59

I've seen the H3+ ion often mentioned as a relatively common hydrogen species in interstellar space. This got me wondering as to whether stable salts have ever been prepared of this ion. It will be no doubt highly acidic, but it could perhaps be formed by reaction of elemental hydrogen with a superacid:

eg. H2 + HSbF6 -> H3(+)SbF6(-)

Any thoughts?

[Edited on 27-8-2006 by Pyrovus]

Nerro - 27-8-2006 at 05:19

Are you sure they don't all say "<sup>3</sup>H<Sup>+</sup>"?

Which would be tritium, a twice deuterated version of hydrogen.

[Edited on Sun/Aug/2006 by Nerro]

12AX7 - 27-8-2006 at 09:13

Twice deuterated would be Li5...

No, he does indeed mean H2(+), i.e, two protons and one electron. H2(0) is more stable, but the molecule will hold together with one electron too.

Let's see, the way those things work, it should also be paramagnetic, right? One (electron) spin, not canceled by another.

Tim

Nerro - 27-8-2006 at 09:53

My mistake, I meant hydrogen with two extra neutrons.

Pyrovus - 27-8-2006 at 16:41

Actually, I was referring to H3+ i.e. three protons and two electrons, the whole system joined together by a three-centre two electron bond.

franklyn - 27-8-2006 at 17:49

Since I'm not a chemist my input here is only somewhat informed.
Identification of some ionic form in outer space tells you nothing
about the time it remains in existence. The signals interpreted are
only for the aggregate occurrence across the vastness.
HeH + , is known but has no existence beyond the nominal.
Research for using hydrogen in exotic forms both monoatomic and
Ionized into ( H + ) and ( H = ) as a means for storing energy say
for rocket propulsion is ongoing but with few practical results that
matter.
An interesting chemical form is Diborane which has a unique protic
bridge bond , sharing a hydrogen thus : See attached image

Ammonia and diborane alone form NH4BH2 but with hydrogen this
forms instead into NH4BH4 ,
NH3 H+ - H BH3

This is the only stable ionic H - H bond I am aware of.
( Hydrazine may also be substituted for ammonia )
NH2NH3.BH4

[Edited on 28-8-2006 by franklyn]

Diborane.jpg - 3kB

12AX7 - 27-8-2006 at 19:27

Oh, H*3*... I seem to remember something about that being present in superacidic conditions... hmm vague. *shrug* Google any help?

Tim

DeAdFX - 27-8-2006 at 20:26

Quote:
Originally posted by franklyn
An interesting chemical form is Diborane which has a unique protic
bridge bond , sharing a hydrogen thus : See attached image

Ammonia and diborane alone form NH4BH2 but with hydrogen this
forms instead into NH4BH4 ,
NH3 H+ - H BH3


[Edited on 28-8-2006 by franklyn]


I don't know if that is possible but Diborane and Ammonia under certain conditions can form a cylic compound which resembles benzene. More information can be found here. http://en.wikipedia.org/wiki/Borazine

woelen - 27-8-2006 at 22:42

Quote:
Originally posted by franklynAn interesting chemical form is Diborane which has a unique protic
bridge bond , sharing a hydrogen thus : See attached image

Ammonia and diborane alone form NH4BH2 but with hydrogen this
forms instead into NH4BH4 ,
NH3 H+ - H BH3

This is the only stable ionic H - H bond I am aware of.
( Hydrazine may also be substituted for ammonia )
NH2NH3.BH4

[Edited on 28-8-2006 by franklyn]

This is not really H, bonded to two boron atoms. The electronic structure of this is quite peculiar.

The H-atoms which are not inbetween have a normal single bond with the boron. This makes their outet shell number of electrons equal to 2, and these H-atoms are happy. The borons then have 4 electrons (2 of the H's and 2 of them selves). These B atoms want 8 electrons, and the other 2 H's want 2 electrons. This is accomplished by a strange bond with a longer orbital, in which 2 electrons are shared by 3 atoms (instead of the usual 2).

For the center H-atoms, the H-atom provides an electron, and one of the boron atoms provides an electron and the bond extends to both boron atoms and the H-atom. So all have a shared 2 electrons. The other H-atom is connected between the borons in a similar way and in this way another 2 electrons are shared. Now the center H-atoms also have 2 shared electrons and both borons have 8 electrons. This type of bond is quite rare, it is called a 3 center 2 electron bond.

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

not_important - 27-8-2006 at 22:55

These seem to be what you are refering to

http://xxx.lanl.gov/abs/cond-mat/9412123

http://www.hs.uni-hamburg.de/cs13/abstract43.html

http://www.pnas.org/cgi/content/abstract/103/33/12235

The last includes the statement "It is the most abundantly produced interstellar molecule, next only to H2, although its steady state concentration is low because of its extremely high chemical reactivity. " That doesn't seem to make it likely it can exist in any real concentration.

And the next says that while it's seen in the outer atmospheres of the gas giants, the molecular density is pretty low

http://www.aas.org/publications/baas/v30n3/dps98/405.htm

http://spaceflightnow.com/news/n0304/06cosmic/