Sciencemadness Discussion Board

Making Methylene Bromide from DCM

ItsAChitzen - 11-7-2012 at 11:23

As stated here,
 
http://www.sciencemadness.org/talk/viewthread.php?tid=14994#...
 
it has been suggested that DCM and Br2 will form CHBrCl2 and HBr. However, I did a few calculations which seems to say that DCM and HBr should lead to HCl and DBrM. Is this ridiculous, or is it just one of many reactions which can proceed?

Nicodem - 12-7-2012 at 05:01

Quote: Originally posted by ItsAChitzen  
it has been suggested that DCM and Br2 will form CHBrCl2 and HBr.

You might want to explain what a radical bromination of CH2Cl2 has to do with a nucleophilic substitution? I will spare you the literature work and tell you that it has nothing in common.
Quote:
However, I did a few calculations which seems to say that DCM and HBr should lead to HCl and DBrM. Is this ridiculous, or is it just one of many reactions which can proceed?

Obviously, it is impossible to comment this, because you give no reference and you don't explain your "calculation" process. Please invest more effort into explaining your idea.

ItsAChitzen - 12-7-2012 at 11:58

Quote: Originally posted by Nicodem  

You might want to explain what a radical bromination of CH2Cl2 has to do with a nucleophilic substitution? I will spare you the literature work and tell you that it has nothing in common.


I thought that they would be competing reactions, and that thermodynamics would come into play as far as percentages of each.

Quote:

Obviously, it is impossible to comment this, because you give no reference and you don't explain your "calculation" process. Please invest more effort into explaining your idea.


Not impossible to tell me if it is ridiculous or not, just impossible to tell me how ridiculous. I did the ⌂G calculation and it came out about -49kj/mole. I did have to approximate the ⌂GFormation for DBM as -29kJ/mole. Hopefully these are the correct units; I don't have my calculations with me.