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I learned that hydrogen bonding is formed from a 'sandwich' of hydrogen and either oxygen, nitrogen, or fluorine where nitrogen, fluorine, or oxygen is the bread.

Will oxygen gas and water form hydrogen bonds? The oxygen-hydrogen sandwich could be made, but oxygen gas has no hydrogen attached. Is it necessary for both molecules to contain hydrogen for hydrogen bonding to occur?

To make it clear, the question is: do both molecules have to contain hydrogen in order for hydrogen bonding to occur?

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  • $\begingroup$ Does my answer actually answer your question? The specific case of whether $\ce{O2}$ engages in hydrogen bonding remains unanswered. Feel free to wait a few days before marking an answer as accepted -- many questions go several days before being marked as answered. $\endgroup$ – hBy2Py Dec 2 '16 at 23:55
  • $\begingroup$ Yes, the O2 was just an example, I was just trying to find if any Hydrogenless molecule can undergo hydrogen bonding $\endgroup$ – user1762507 Dec 3 '16 at 5:08
  • $\begingroup$ Semantics - Oxygen gas doesn't form hydrogen bonds with water. Oxygen gas can dissolve in water and once dissolved it will form hydrogen bonds. But dissolved oxygen in water isn't oxygen gas. $\endgroup$ – MaxW Dec 1 '17 at 19:58
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To make it clear, the question is: do both molecules have to contain hydrogen in order for hydrogen bonding to occur?

No, as noted by Prakhar in his answer, tertiary amines are one class of compounds that can participate in hydrogen bonding (as an acceptor) when there is no hydrogen atom directly bound to the participating atom.

As an example, trimethylamine can hydrogen bond just fine with water:

trimethylamine hydrogen bonded to water

More information can be found, e.g., here at ChemGuide (scroll down to "Solubility in water").

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Yes both the molecules should have Hydrogen atoms for Hydrogen bonding to take place.

For instance there would be no hydrogen bonding between Water(H2O) and Oxygen(O2). Since in oxygen both the atoms are equally electronegative therefore there is no partial charge developed.

Whereas in water a partial charge is developed due to higher electronegativity of Oxygen compared to Hydrogen. Thus Oxygen becomes partially negatively charged whereas the hydrogen becomes partially positively charged.

But water and oxygen wont form hydrogen bonds due to lack of partial charge separation in oxygen.

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Here since both the oxygens are equally electronegative there is no charge separation.

NOTE:This is mostly true except for very rare cases such as hydrogen bonding between water and tertiary amines.

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    $\begingroup$ This is not strictly true -- the hydrogen bond acceptor atom does not need to have a hydrogen bonded to it. Consider tertiary amines, for example. $\endgroup$ – hBy2Py Dec 2 '16 at 20:25
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    $\begingroup$ Ok... and what I said is fully consistent with Wikipedia. It says nothing about a hydrogen needing to be bonded to the acceptor atom. $\endgroup$ – hBy2Py Dec 2 '16 at 20:30
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    $\begingroup$ Secondary amines do have a hydrogen bonded to the nitrogen. It's only the tertiary amines that are a counterexample to your stated principle. $\endgroup$ – hBy2Py Dec 2 '16 at 20:33
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    $\begingroup$ Well, problem is that you are wrong about need of partial negative charge on acceptor. Also H-bonding isn't limited those three elements. $\endgroup$ – Mithoron Dec 2 '16 at 21:29
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    $\begingroup$ Hydrogen bonding is limited to only Nitrogen, Oxygen and Fluorine. And yeah @Mithoron give an example where the acceptor atom bears a positive partial charge. $\endgroup$ – Prakhar Dec 3 '16 at 13:50

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