p-benzoquinone via h2o2 results

[blaaky]

Hi

This is my first attempt at making para-benzoquinone. Purchased p-benzo has always been dark greenish color.

I tried to follow overclock's post using some photo hydroquinone

Post 257969 (missing)

(overclock: "p-benzo via H2O2 etc ...", Newbee Forum)
but my addition funnel ended up leaking out of the teflon stopcock so i dumped in all the h2o2 after about 20 minutes, temp shot up to over 80C, started boiling. i cooled it back down after about 15 minutes and kept the temp between 35-40C for 3 hours, then 40-45C for another 3 hours, rxn vessel was left to cool for 30 mins, then refrigerator for an hour and freezer for an hour, then vac filtered and washed 3 times with room temp (forgot to chill it) 91% IPA. Yeild from 55g of hydroquinone was 57g of damp yellow crystals.

what does everyone think of the color of this benzo?


I've done a lot of searching and found conflicting reports about the color, some posts say yellow is pure, some posts say yellow is decomposed and green is pure, others say green is quinhydrone (benzoquinone + hydroquinone).

I left that small ammount of benzo out in the open air to see if it decomposes
Thanks
blaaky

[nitrous351]

blaaky,
  Try a recrystallization to see if the color changes to green/yellow. Did you take a melting point on your crystals? A melting point is worth a thousand words usually. At this point (with the information you gave) I would say if you do actually have p-benzo, it needs to bee cleaned with recrystallization. Recrystalize, do a melting point, then post the results of that.... we'll have more information to work with. peace good luck

[OcoteaCymbarum]

from this post

Post 443537

(Vitus_Verdegast: "yellow and green p-benzoquinone", Chemistry Discourse)

Looks like pee-green is fine, I get excellent results, more then MM claim with a benzo that color

[blaaky]

will try recrystalizing tonight... melting point... i UTFSE'd and didn't find much. I don't have a melting point device but I will try to purchase one soon.

thanks for the suggestions
blaaky

[acid_egg]

Check out the mineral oil device on this page...no purchase necessary!(assuming you own a heating device, a beaker, thermometer and some capilliary tubes.)

http://wulfenite.fandm.edu/labtech/melting.htm