I am doing an experiment functionalize CNT via 3 steps: oxidation, acyl-chlorination, and amidation. At step 2, carboxylated CNT was treated with a mixture of SOCl2 and DMF (20:1) at 70oC for 24h. Then the acyl-chlorinated CNT was centrifuged and washed with THF for 5 times before going to step 3. However, I suppose the COCl groups be moisture-sensitive and could easily be reversed to COOH groups when exposing to the atmosphere.
What is the method to treat the acyl-chlorinated CNTs without making the impact on COCl groups?
Use dry DMF and THF for reaction and washing. The moisture content should not more than 0.05%. Trying to do the all experiment in anhydrous conditions or in glovebox.
Instead of doing centrifugation, carefully distill off the thionyl chloride right from the reaction. Then add a large (5-10x) excess of very dry amine/amine solution to the "crude", dry acyl chlorinated CNTs. You can also just add 1 eq of your amine along with a bunch of non-nucleophilic amine like triethylamine, you just need something to counteract the HCl that is leftover from the chlorination and forms during the amidation.
After it reacts you can do your centrifugation, and the CNTs are never exposed to ambient air in reactive form.
Exposing COCl-CNT to air to wash and centrifuge them is pretty much going to instantly hydrolyze them. Even your THF probably will have enough water to kill it.
I confirm. It is necessary to distill off the thionyl chloride under vacuum.
Add dry toluene and carefully distill off all liquid under vacuum.
Then again add dry toluene and the desired amine.
Next, the entire mixture was heated in an ultrasonic bath at 70C for 24 hours minimum.
I hope you do not experiment with 10 mg SWCNT. http://ocsial.com/en/
- Badges
- Science topic
- Similar topics
- Chemistry
- Organic Chemistry