Sciencemadness Discussion Board

Determining Carbene Loading on Polymer Supported NHC

jw1095 - 21-7-2014 at 15:01

I am trying to determine the Thiazolium loaded onto Merrifield Peptide Resin. The benzyl chloride loading is 3.5-4.5mmol/g. My rough thinking is calculate maximum posible loading based on the 3.5-4.5mmol/g. Then react the MPR-TMCl salt with that amount of strong base to compleatly de-protonate any NHC present, then filter off the MPR-TM and back titrate till neutral. Subtract moles of acid from moles of strong base to calculate moles of NHC present.

Would I need a base like K-tert-Butoxide, or would NaOH be sufficient?

Is it plausible to do this type of titration with say 100mg of MPR-TMCl?