Hydrogen bonds can form between two hydroxyl groups. Is the hydrogen bond stronger if one of the groups is deprotonated?
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1$\begingroup$ Yes, if the one on the left is deprotonated, the hydrogen bond shown will be stronger. The opposite is true for the one on the right. $\endgroup$– Karsten ♦Commented Aug 17, 2021 at 20:58
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1$\begingroup$ Thanks. Ah I managed to read up on that, or, understand it since it was pretty easy. The one on the right, if it is deprotonated, that would prevent any bond forming at all with it as the donor, right? Since it can't donate much anymore. $\endgroup$– MarioCommented Aug 17, 2021 at 21:00
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$\begingroup$ @KarstenTheis An interesting observation. The deprotonated group, it has, relatively speaking, less negative charge. Otherwise, it would be able to hold onto the proton just as well. And since the hydrogen bond acceptor is the group with most negative charge, the deprotonated one would only be favoured because it lacks the proton, not because is has less negative charge in itself. $\endgroup$– MarioCommented Aug 18, 2021 at 11:01
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$\begingroup$ @NilayGhosh I'm actually looking at the issue from a very unusual angle. So my complete self-answer would include it. The thing is, I think that, if introduced in a "lock and key" setting with a specific type of fit, the deprotonated group might actually be the hydrogen bond donor. This is very counter-intuitive, but, it relies on the groups being forced close to each other to start with. Then, the combined negative charge of the groups, will actually protonate the deprotonated group, and it will be the donor the the more negatively charged other group. $\endgroup$– MarioCommented Aug 18, 2021 at 11:03
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$\begingroup$ @NilayGhosh What I did was I wrote the answer that was the one I was looking for (plus the simple answer Karsten gave. ) I think it is factually correct. What it lacks is context, but, I know the context already, it just takes a bit of time to communicate it so I left it out. So in this context, I just require it is factually correct even if the scenario seems far fetched, and it seems right to me. It also points people to the fact that the deprotonated group is actually deprotonated because it is "relatively speaking" "less negative", an interesting observation. $\endgroup$– MarioCommented Aug 18, 2021 at 11:52
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