exciton - 31-8-2011 at 15:46
The literature says to use trichlorobenzene and bring the temperature to over 200*C and then filter and wash the product with benzene. Since TCB is a
hazardous material, I'd like to use a different (cheap?) aprotic non-polar solvent with a similar boiling point. Any suggestions?
Thanks!
not_important - 1-9-2011 at 06:36
Depends on the reactants different solvents may or may not be compatible with the reagents and products.
exciton - 1-9-2011 at 09:24
Reagents are: pyromellitic dianhydride and urea. The product will be poly-phthalocyanine.
Any suggestions?
exciton - 6-9-2011 at 19:40
Okay, so I figured out that the _test tube_ containing pyromellitic dianhydride and urea is placed in a high boiling point solvent (such as
dipropylene glycol) but the contents _in_ the test tube are not solvated by them. In other words, if I understand this correctly, the reactants
remain dry.
I'll eventually give it a try. I'm excited to see if I can produce a cheap organic polymer solar cell from a poly-phthalocyanine dye precursor. 
fledarmus - 7-9-2011 at 04:25
Then you're just using the trichlorobenzene as a heating bath?
For 200*C, I think I would switch to a sand bath. That's a little high for the mineral oil baths I would otherwise suggest, and high-temp silicon oil
is pretty pricey.
ScienceSquirrel - 7-9-2011 at 05:36
You could try diphenyl ether; widely used for ring closures, decarboxylations, etc.