What would be the good method and solvent to purify biphenyl?

  • Thread starter Thread starter Fairway
  • Start date Start date
  • Tags Tags
    Method Solvent
Click For Summary

Discussion Overview

The discussion revolves around methods and solvents for purifying biphenyl contaminated with fluorene, focusing on the differences in polarity and melting points of the two compounds. The context includes considerations of crystallization and solvent extraction techniques.

Discussion Character

  • Homework-related, Technical explanation, Conceptual clarification

Main Points Raised

  • One participant suggests that crystallization might be a good method for purifying biphenyl, noting the difference in melting points between biphenyl and fluorene.
  • Another participant points out that fluorene has an acidic proton and can be deprotonated by NaOH, indicating a potential method for separation.
  • A different participant raises a question about the solubility of fluorene in polar solvents and the behavior of biphenyl when mixed with NaOH and ether.
  • One participant expresses confusion about the purification process but acknowledges that NaOH and ether could effectively separate biphenyl from fluorene, with biphenyl remaining in the ether phase.

Areas of Agreement / Disagreement

Participants express varying levels of understanding and confidence regarding the purification methods. There is no clear consensus on the best approach, and some participants remain uncertain about the implications of using different solvents.

Contextual Notes

The discussion does not resolve the specific conditions under which biphenyl and fluorene can be effectively separated, nor does it clarify the assumptions regarding solvent interactions and compound behavior in different phases.

Who May Find This Useful

Students and practitioners interested in organic chemistry, particularly those dealing with purification techniques and solvent interactions in laboratory settings.

Fairway
Messages
8
Reaction score
0

Homework Statement



what would be the good method and solvent to purify biphenyl contaminated with fluorene?


Homework Equations







The Attempt at a Solution



The polarity of biphenyl (MP: 68.93°C) and fluorene (MP: 116-117°C ) are same which is non polar but their MP is hugh different. So, I'm not so sure which solvent is good to use. I think cryatallization would be the good method to purify. Could you help on this? Thank you so much.
 
Physics news on Phys.org
Fluorene has an acidic proton and the anion is stabilized by aromatic stabilization. NaOH is apparently a strong enough base to deprotonate it.

You could also use an alcohol like butanol or butanol + ether.
 
Thanks for help, It's kind of still confusing becaue the question is asking about to purify the biphenyl from fluorene.
 
Fluorene is somewhat acidic (NaOH can deprotonate it) and is therefore more polar than biphenyl. It would more soluble in a polar solvent like alcohol. What would happen if you were to shake a sample containing fluorene with NaOH and ether? Would you find the fluorene in the organic or the aqueous phase? Would the biphenyl stay in the ether phase or would it cross over into the aqueous phase as well?
 
Thank you so much. It makes sense NaOH and ether will sepearte biphenyl from Fluorene because biphenyl will stay in ether phase. If I understood this earlier, then I would have got the right answer for my lab. Well, Still I'm so happy that I know now. Thank you again!
 

Similar threads

  • · Replies 7 ·
Replies
7
Views
2K
Replies
0
Views
2K
  • · Replies 1 ·
Replies
1
Views
2K
  • · Replies 1 ·
Replies
1
Views
3K
Replies
1
Views
6K
  • · Replies 36 ·
2
Replies
36
Views
8K
  • · Replies 1 ·
Replies
1
Views
3K
  • · Replies 2 ·
Replies
2
Views
2K
Replies
2
Views
2K
  • · Replies 7 ·
Replies
7
Views
5K