Timeline for Why is phenol more acidic than aniline?
Current License: CC BY-SA 3.0
10 events
| when toggle format | what | by | license | comment | |
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| Apr 28, 2021 at 13:23 | answer | added | Safdar Faisal | timeline score: 2 | |
| May 2, 2019 at 14:56 | comment | added | Harsh Wasnik | The hydrogen of phenol is more acidic than that of aniline due to greater electronegativity of oxygen | |
| Dec 8, 2017 at 18:14 | comment | added | Mithoron | Same reason that water is more acidic then ammonia. | |
| Dec 8, 2017 at 10:57 | comment | added | orthocresol | The electronegativity scale is essentially arbitrarily constructed, there’s little reason to expect that there should be a quantitative correlation. Maybe there is, I don’t know, but you can’t say that an electronegativity difference of 0.5 “looks small to me” so the pKa difference “shouldn’t be so large”, or anything along those lines. | |
| Dec 8, 2017 at 10:55 | comment | added | Arishta | Is the difference between their electronegativities too large to explain the pka difference of 15. Nitrogen is 3 and oxygen is 3.5 on Pauling scale of electronegativity. | |
| Dec 8, 2017 at 10:52 | comment | added | orthocresol | Ok, I see now. Electronegativity is usually the main factor. The pKa difference between alcohols and amines is ~20 which is quite large; a difference in the extent of resonance delocalisation isn’t likely to affect pKas by that much. (Compare for example methane (pKa 50) vs toluene (41). In your example both molecules are resonance stabilised so the difference due to this should be much smaller.) | |
| Dec 8, 2017 at 10:45 | history | edited | Arishta | CC BY-SA 3.0 |
added 107 characters in body
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| Dec 8, 2017 at 10:43 | comment | added | Arishta | @orthocresol After deprotonation, the negative charge will be more delocalized in the case of aniline because of greater +M effect of nitrogen. Since the anion is more stable, aniline should be more acidic. | |
| Dec 8, 2017 at 10:27 | comment | added | orthocresol | What does point 2 have to do with this? I don’t see the link. | |
| Dec 8, 2017 at 9:42 | history | asked | Arishta | CC BY-SA 3.0 |