Sciencemadness Discussion Board

Br Related

newboy - 17-12-2006 at 21:52

I have some Bromo Chloro Dimethylhydantoin Tablets and was wondering could anyone help with with regards to seperating the Br out of it. It may allready be posted and i will be serching for it but if you can point me in the right direction will save me heaps of time......thanks guys

Blind Angel - 17-12-2006 at 22:04

Not sure it's possible, I'm not exactly sure what is the molecule you are talking about but if the Br has a covalent bond with a C it'll be very hard get it out, specialy since you have only one of those Br atom by molecule so yield would be extremely low. I'm starting to wonder if decomposing the substance by heating would be possible, but in that case i'm pretty sure that the Br would evaporate. In any case, I'm pretty sure though that anybody who would have the competence to get that Br out would have access to analytical grade Br anyway.

Pyrovus - 17-12-2006 at 22:10

Bromo chloro dimethylhydantoin has the bromine and the chlorine covalently bonded to nitrogens:

Nicodem - 18-12-2006 at 12:10

Quote:
Originally posted by newboy
I have some Bromo Chloro Dimethylhydantoin Tablets and was wondering could anyone help with with regards to seperating the Br out of it. It may allready be posted and i will be serching for it but if you can point me in the right direction will save me heaps of time......thanks guys

What do you mean by "seperating the Br out of it"? Are you asking about preparing bromine (Br2) out of N-bromo-N'-chloro-dimethylhydantoin? If that is the case, please UTFSE before you ask already discussed questions and open obsolete threads! The directions on how to prepare Br2 from N-bromo-N'-chloro-dimethylhydantoin were already given at the end of this thread.

hinz - 18-12-2006 at 15:06

Wouldn't it be possible to lead HCl gas in a two neck flask containing n-bromo n-chloro-dimethylhydantoin? The structure reminds me to the structure of trichloroisocyanuric acid (TCCA) with halogens bond to nitrogen bond to two other carbonyl groups. So the halogen is a electrophile due the resonance stability in
(-)N-C=O <==> N=C-O(-).
(The reactivity is decreased compared to TCCA, because TCCA should be aromatic (stability) if all halogens have left and the tripple charged anion has 3 double bonds in a 6-membered ring. On the other hand the reactivity could be increased by the better formation of Br+ in n-bromo n-chloro-dimethylhydantoin)

If this is the same here, so I suppose it will give Cl2 and Cl-Br with HCl, like with TCCA, by the attack of Cl- from HCl on Cl+ and Br+ from n-bromo n-chloro-dimethylhydantoin. Because Br is less electronegative (easier to leave as a cathion) I think Cl-Br will be formed first. This compond could be trapped in a cold trap as it has a boiling point of 5°C.
The Br-Cl could be decomposed by heating later or futher used as a reagent. But n-bromo n-chloro-dimethylhydantoin could be used also in mixed chlorinations and brominations, so I would use it in the same reactions as TCCA is used


[Edited on 18-12-2006 by hinz]