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

[Fairway]

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.

 

[chemisttree]

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.

 

[Fairway]

Thanks for help, It's kind of still confusing becaue the question is asking about to purify the biphenyl from fluorene.

 

[chemisttree]

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?

 

[Fairway]

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!