Question

I have phenanthrene and 1,4-dibromobenzene dissolved in methylene chloride. I need to purify and crystallize the phenanthrene. What should I use as my hot solvent to do this?

Answer 1

Phenanthrene and 1,4-dibromobenzene are dissolved in methylene chloride.

Now, both of the two compounds are also soluble in non-polar solvents like Benzene or toluene or hexane. So, in this case your choice of solvent is not going to help.

You need to purify through column chormatography and recrystalize in hexane or benzene.

Solvent selection for purifying through recrystalization helps when there is some polarity difference. But in this case, you don't have that option, since both of the compounds will dissolve even in nonpolar solvent. Your both compounds are in dichloromethane. So, first evaporate dichloromethane and do column chromatography.