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Screenshot of my lecture I'm currently studying aromatic compounds via online recorded lectures, and my teacher brought up about cyclopropenol and cyclopropenylhydroxide while teaching carbocylic non benzenoid compounds. He said the latter exists while the former doesn't exist; and due to time restrictions they cut off the part where he explains the reason, out of the video. So why doesn't it exist?

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    $\begingroup$ What is "cyclopropenylhydroxy"? That's not a valid chemical name. "Cyclopropenol" could refer to one of two isomers, which is it? Do you have structures which you could draw? $\endgroup$ – orthocresol Dec 3 '20 at 14:37
  • $\begingroup$ @orthocresol Thank you for suggesting the changes. I'm a high school student and am pretty much new to all this stuff, so forgive me if I didn't provide all details required in order to help people answer the question properly. I've made the changes and attached an ss of my video lecture, so I hope that helps ;) $\endgroup$ – Anirudh Narayan Dec 3 '20 at 15:03
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    $\begingroup$ OK, no problem. Now, I'm really not sure whether what you're being taught is legit. The former seems to exist just fine at low temperatures, and was apparently reported in 1984, although I can't find any references to it since then. I would be extremely skeptical of the latter actually existing. I highly doubt that a carbocation can form a stable salt with something as basic as hydroxide ion. $\endgroup$ – orthocresol Dec 3 '20 at 15:37
  • $\begingroup$ @orthocresol the teacher said that the former dissassociates into the latter cause of the aromatic character [ Unusual stability ] since the latter follows all the 4 rules for aromaticity [ cyclic, huckel's rule, planar and conjugated pi electrons ]. He added that the former doesn't follow the huckel's rule which I'm finding trouble understanding since I couldn't get the difference in no. of pi electrons in both the compounds since there is only double bond [ away from the OH atom/cation ]. $\endgroup$ – Anirudh Narayan Dec 3 '20 at 16:03
  • $\begingroup$ Aromaticity and all that is fine, but it's still a carbocation. Aromaticity doesn't suddenly make a carbocation more stable than a neutral compound. To use a different example, this is almost like suggesting that cyclopentadiene should spontaneously dissociate into cyclopentadienyl plus a proton, because the anion is aromatic. But, you probably know enough chemistry to look up the pKa of cyclopentadiene and figure out where that equilibrium lies. (Hint: the pKa is 16.) As for Huckel's rule in the alcohol, it is not relevant at all, because the pi system does not extend over the whole ring. $\endgroup$ – orthocresol Dec 3 '20 at 16:31

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