1. Standard Operating Procedure: Stills for drying solvents (shared with DOH group)
Alice Leung 08/12/2016

2. What do they do? Used for drying solvents:
THF
Toluene
Hexane
Pre-dried over KOH or molecular sieves (4 Å)
THF – NEVER dry with KOH, generation of peroxide possible
Refluxed over sodium/benzophenone (indicator):
Blue/purple = DRY
Yellow/orange = WET
Hexane – indicator sparingly soluble (triglyme)

3. deep blue radical anion
Sodium/benzophenone indicator
Indicator of dryness of stills
Hazard – SODIUM under reflux in flammable solvents!
Build up of NaOH – stills must be changed every 3-4 months
deep blue radical anion
purple dianion

4. YOU MUST BE A TRAINED USER TO OPERATE SOLVENT STILLS
Before use…
YOU MUST BE A TRAINED USER TO OPERATE SOLVENT STILLS
Trained users from the group
Alice Leung & Arron Deacy
THF stills maintained by DOH group:
Dr Jean-Charles (JC) Buffet
Dr Zoë Turner
Dr Sandy Kilpatrick

5. THF stills connected to same N2 supply
Stills set up in CRL (room opposite lab S8)
Goicoechea group
(THF)
O’Hare group
(THF)
Aldridge group
(…..)
THF stills connected to same N2 supply
Water ON (before switching stills on)
Log book

6. Mercury bubbler (ONLY for collection)
Set up (stills on – N2 flow and water on)
N2 in
N2 out
Collection funnel
Water condenser
Collection tap
Paraffin bubbler
Mercury bubbler (ONLY for collection)

7. Collection tap - HORIZONTAL
Collection of THF
Solvent MUST be refluxing before collection
Switch off Goicoechea stills (if on)
Inform a member in Goicoechea group (unplug from wall socket)
Collection tap – horizontal
Allow mins for condensation of THF ( mL) in condenser
Once collected
SWITCH OFF power by removing plug from the main on wall
Allow to cool (1-1.5 hrs)
Collection tap - HORIZONTAL

8. Collection of THF – stills cooled
ONLY ampoules with Young’s tab and metal cannula can be used
(1) Switch N2 bubbler from parrafin to mercury
High pressure to push solvent out through need into ampoule
(2) Purge cannula and ampoule using stills N2 flow (ref. SPS collection) then collect
Collection done
(3) collection tap returned to vertical position
(4) bubbler slowly switched back to parrifin 2 1 3 4

9. Collection finished
Switch both O’Hare and Goicoechea (if it was on before) stills back on
NO exposed Na seen
H2O flow on
N2 flow on
INFORM both groups that solvent collection is done and stills are on
N2 in
N2 out
Water condenser
Paraffin bubbler

10. Remember…
Always write in log book to what you have done with both THF stills
MUST be counter-signed by O’Hare (JC, Zoë or Sandy) and Goicoechea group (David Lo)
Do’s
Check with O’Hare group that it is good to collect THF
Preferably collect towards end of week
Inform Goicoechea group
Unplug heating mantles from the main wall sockets
No chance of accidentally switching stills back on
Water is always on when stills is on
Don’ts
Let stills boiled dry!!!
Use mercury bubbler when refluxing
Let air get into system
Overfill stills
Leave stills on for collection for a long period of time when collection funnel is full

11. If in doubt…
PLEASE ASK!

12. Disposal of stills
Disconnect stills from set up carefully without letting air in
Keep stills under N2 atmosphere
Under a dynamic flow of N2 and stills keep cold using ice bath
Slowly add in IPA/toluene with stirring until stills turn yellow/orange
Slowly add in IPA/water
Warm stills mixture to room temperature
Expose stills mixture to air and stir overnight
Dispose of the mixture as hydrocarbon waste
Procedure MUST be performed in fumehood