Drying agents and cooling baths template

Drying agents (MgSO₄, Na₂SO₄, CaCl₂, K₂CO₃, 3Å and 4Å sieves) with capacity, speed, use and what to avoid, beside a table of cooling baths from ice/water (0 °C) to liquid nitrogen (−196 °C).

What the template shows

• Pick the drying agent for the solvent, and the bath for the temperature
• Drying agents for organic solutions
• Good for
• Avoid / note
• General work-ups; fine powder, filter it off
• Very acid-sensitive compounds (slightly Lewis acidic)
• General, neutral; granular, decant off
• Leaves more water; useless above 32 °C
• Hydrocarbons, alkyl halides, ethers; drying tubes
• Alcohols, amines, carbonyls, acids (complexes)
• Amines, ketones, basic solutions
• Acids and phenols (reacts)
• 3Å molecular sieves
• slow (h–days)
• MeOH, EtOH, MeCN to ppm water; only H₂O fits
• Activate first (300 °C, vacuum); dust
• 4Å molecular sieves
• THF, DCM, toluene, DMF, ethers
• MeOH, MeCN (taken up too); activate first
• Capacity: water taken up per gram of agent. Speed: time to dry a typical work-up solution (MgSO₄ minutes; Na₂SO₄ 15–30 min; sieves hours to days).
• Sieves: use 10–20% w/v of activated beads and leave the solvent standing on them (24–72 h) for ppm-level water.
• Cooling baths
• Ice / water
• Ice / NaCl (3:1 w/w)

Drawn with 4 atoms, 21 shapes – every one editable in MolDraw.

Sources

• Armarego, Purification of Laboratory Chemicals, 9th ed., Elsevier 2022 Textbook
• CRC Handbook of Chemistry and Physics, 104th ed., CRC Press 2023 Textbook