Sciencemadness Discussion Board

"Perchloro" organics

chornedsnorkack - 26-3-2018 at 10:24

What is known about, and how are called, compounds with structural fragment O3Cl-C?
In analogy with compounds called "nitro" compounds, with structural fragment O2N-C, the fragment O3Cl-C should be called "perchloro".
But "perchloro" is also used for organic compounds that lack C-H bonds, having only C-Cl bonds, but no Cl-O bonds.

So what is specific term for O3Cl-C?

Thulium - 26-3-2018 at 11:00

I suspect this may be a case of "if you can isolate it, you can name it". A very quick scan of the literature on the internets shows no references to any of these compounds. This isn't terribly surprising to me since perchlorate esters are already incredibly unstable (http://www.sciencemadness.org/talk/viewthread.php?tid=1081) and the perchlorate anions stability is largely due to the closed shell provided by the four highly electronegative oxygens. Replacing an oxygen with a carbon would eliminate this last stabilizing force. As for why perchlorocarbons are called such, I suspect it's to be analogous with perfluorocarbons in which case there is no possibility of confusion with "perfluoric acid".

I would love it if you, or anyone, can prove me (and whoever named the "perfluorocarbons") wrong on this by synthesizing what I would suspect to be s very energetic material indeed :)

Σldritch - 26-3-2018 at 11:53

If you have access to a cyclotron you could make perhaps it from perchloramide.
N13H2ClO3 ---> C13H2ClO3• + ve

Before you try it though, i have only read of Perchloramides being made from secondary amines, the electron donation from them might help with stability too. Note that it would be a radical.

Playing around a bit with resonance structures this is the most stable looking thing i can find. As for a name, they are similar in structure to Nitronic acids so i would suggest Perchloronic acids if they exist, which they probably do not, but here is a picture anyway:

PerchloronicAcids.jpg - 7kB

[Edited on 26-3-2018 by Σldritch]

Thulium - 26-3-2018 at 15:29

This question sort of bugged me all day today, and I was thinking maybe something similar to a Wurtz reaction could be done with Perchloryl Fluoride (which is amazingly stable for such a cluster of electronegativity). Looking at the wikipedia page for Perchloryl Fluoride (https://en.wikipedia.org/wiki/Perchloryl_fluoride), it seems there are two references to what they call "alkyl perchlorates" (somewhat ambiguous term with perchlorate esters) being formed in a Friedel-Krafts type reaction with Perchloryl Fluoride and hydrocarbons, featuring the C-ClO3 bond the OP described. I unfortunately do not have access to either of the books cited though to verify that they do in fact mention these compounds being characterized.

DraconicAcid - 26-3-2018 at 17:10

You mean perchloryl compounds? https://en.wikipedia.org/wiki/Perchlorylbenzene

chornedsnorkack - 27-3-2018 at 06:57

Quote: Originally posted by Thulium  
This question sort of bugged me all day today, and I was thinking maybe something similar to a Wurtz reaction could be done with Perchloryl Fluoride (which is amazingly stable for such a cluster of electronegativity). Looking at the wikipedia page for Perchloryl Fluoride (https://en.wikipedia.org/wiki/Perchloryl_fluoride), it seems there are two references to what they call "alkyl perchlorates" (somewhat ambiguous term with perchlorate esters) being formed in a Friedel-Krafts type reaction with Perchloryl Fluoride and hydrocarbons, featuring the C-ClO3 bond the OP described.


Alkyl or aryl?

The original works with perchloryl fluoride and aluminum chloride (sic!) were late 1950s. 60 years ago.
If what you want is electrophilic perchloryl cation then you have other fluoride acceptors. For nitration, a popular reagent is nitryl tetrafluoroborate, NO2BF4.
So what can be used to make ClO3F more electrophilic? BF3??PF5?AsF5?SbF5?

Thulium - 28-3-2018 at 00:04

Quote: Originally posted by chornedsnorkack  


Alkyl or aryl?

The original works with perchloryl fluoride and aluminum chloride (sic!) were late 1950s. 60 years ago.
If what you want is electrophilic perchloryl cation then you have other fluoride acceptors. For nitration, a popular reagent is nitryl tetrafluoroborate, NO2BF4.
So what can be used to make ClO3F more electrophilic? BF3??PF5?AsF5?SbF5?


First a thanks to DraconicAcid for clarifying these compounds do exist and are called Perchloryls, and presumably aryl if we are talking about perchlorylbenzene.

This is new territory for me, but for there synthesis, it looks like it can be done in water with AlCl3 acting as the fluoride acceptor, producing HCl in the process.

Now I'm now if anyone's ever synthesized Perchloryl Methane... The fuel to oxidizer ratio looks... energetic :)

chornedsnorkack - 28-3-2018 at 08:25

Turns out BF3 can be used for perchlorylation of aromatics but is less active than AlCl3. Reported by Olah, 2003 - source is from 1966, JACS 88, 3819. Inmann et al.