MXG
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black crud
I have been making o and p nitrophenol dyes by routine nitration of phenol under mild conditions. This has worked well enough, but what is the black
tary crud that always forms along with my product? I seem to make it no matter how cold I keep it or how slowly I add reactants or how steadily it is
stirred. I know that organic chemistry often makes black crud but I am simply curious what it might be. I sometimes get it with diazotizations too. Is
it some polymer? If it is a side-product what might it be? My own limited analysis hasn't told me too much. Thank-you!
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Nicodem
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Thread Moved
8-4-2013 at 11:34 |
Nicodem
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You can check with TLC to see if your "black crud" is just a complex mixture of compounds or a true tar (undefinable mixture of polymeric crap).
…there is a human touch of the cultist “believer” in every theorist that he must struggle against as being
unworthy of the scientist. Some of the greatest men of science have publicly repudiated a theory which earlier they hotly defended. In this lies their
scientific temper, not in the scientific defense of the theory. - Weston La Barre (Ghost Dance, 1972)
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kristofvagyok
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In organic chemistry there are always some side reactions what also happens next to your main route, these often form polymers, oxidation products and
a lot thing what you don't want to see, but sadly they are almost always there...
But see the good point: unless the tar is in a smaller percent than your product it couldn't be as bad...
I have a blog where I post my pictures from my work: http://labphoto.tumblr.com/
-Pictures from chemistry, check it out(:
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MXG
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Thank-you for the useful feedback!
I tried the TLC and found where some of my yield has been hiding.
I am encouraged that black crud is not too unusual - I think I will worry about it less in the future.
Thank-you!
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