Info For  Group Members

Drying of Deuterated Solvents

P2O5 as drying agent

CD2Cl2, C6D5Cl, C6D5Br, CDCl3, ClD2CCD2Cl, Cl2DCCDCl2
  1. Place P2O5 in round bottom flas in glove box. P2O5 should be a white, free-flowing powder.
  2. Outside glove box, pour solvent over P2O5. Place solvent under a static N2 pressure. Stir for 1-2 days, the longer the better.
  3. Freeze-pump-thaw solvent 3 times.
  4. Freeze-pump-thaw: Place liquid N2 bath around flask (N2 level BELOW the level of the solvent). Once solvent is frozen solid open vessel to vacuum. When flask is under full vacuum, seal flask and warm to RT.
  5. Vacuum transfer degassed solvent into a dried storage container. Label the container. Take a reference spectrum with an internal standard, e.g. C6Me6, to determine the amount of residual water.
Na/benzophenone as drying agent

benzene-d6, toluene-d8, THF-d8

For benzene and toluene:
  1. In glove box, place Na/benzophenone in round bottom flask with stir bar and attach 180 deg adapter.
  2. Add the solvent in the box. Attach to line. freeze-pump-thaw 3 times.
  3. Stir under static vaccum for several hours.
  4. Attach hot vacuum transfer flask to line and evacuate. Let flask cool to RT under a dynamic vacuum. Once at RT, seal flask.
  5. Vacuum transfer dried solvent from Na/benzophenenone to empty, dried storage flask. Label flask.
For THF:
  1. In glove box, place Na/benzophenone in round bottom flask with stir bar and attach 180 deg adapter.
  2.  Attach flask to line and evacuate. Once flask is evacuated, seal flask.
  3. In separate Schlenk vessel, add desired amount of THF-d8. freeze-pump-thaw 3 times.
  4. Vacuum transfer degassed THF-d8 to flask containing Na/benzophenone.
  5. Stir under static vaccum for several hours.
  6. Attach hot vacuum transfer flask to line and evacuate. Let flask cool to RT under a dynamic vacuum. Once at RT, seal flask.
  7. Vacuum transfer dried solvent from Na/benzophenenone to empty, dried storage flask. Label flask.
CaH2 and 4A Mol Sieves as Drying Agent

 DMSO-d6 and CD3CN

Attention: Molecular sieves have to be dried at >150 deg in the vacuum for at least 12 h.
  1. In glove box place CaH2 in round bottom flask with stir bar and attach 180 deg adapter.
  2. Pour solvent quickly in round bottom flask  outside of the box. Place flask under N2 atmosphere.
  3. Freeze-pump-thaw 3 times. Warm to room temperature and stir for 12 h under static vacuum.
  4. In the case of DMSO perform two more  freeze-pump-thaw procedures after stirring.
  5. In glove box place 4A mol. sieves in a dry storage flask (Schlenk flask with stir bar in the case of CD3CN).
  6. Attach to line and place under vacuum.
  7. Vacuum transfer solvent to storage flask. These solvents are stored over molecular sieves.
  8. For CD3CN stir for 12 h and vacuum transfer to another storage flask with 4A mol. sieves.
Acetone-d6
  1. In glove box place 4A mol. sieves in round bottom flask with stir bar and attach 180 deg adapter.
  2. Pour solvent quickly in round bottom flask  outside of the box. Place flask under N2 atmosphere.
  3. Freeze-pump-thaw 3 times. Warm to room temperature and stir for 12 h under static vacuum.
  4. In glove box place more 4A mol. sieves in a dry storage flask
  5. Attach to line and place under vacuum.
  6. Vacuum transfer solvent to storage flask. Acetone-d6 is also stored over molecular sieves.