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Important Safeguards
Important Safeguards
General guidelines for safe operation of the MARS 6 Synthesis system are presented below and all specic safety
messages are located throughout the manual.
Proper precautions must be taken to avoid contact with reagents or reagent vapors. Protective gear should be worn
as outlined in the user’s safety program for hazardous materials and the reagent manufacturer’s safety data sheet.
Refer to these guidelines for proper handling and disposal of the reagents. Dispose of all waste in accordance with
all applicable local, state, and federal health and safety recommendations.
Solvent Chart
The below chart provides some representative examples of microwave absorptive properties for a variety of
common synthetic solvents. For solvents not included in this chart, contact your CEM representative.
Microwave Absorbency Solvent
High DMSO, EtOH, MeOH, Propanols, Nitrobenzene, Formic Acid, Ethylene Glycol
Medium Water, DMF, NMP, Butanols, Acetonitrile, HMPA, Methyl Ethyl Ketone, Acetone and other ketones,
o-Dicholorbenzene, 1,2-Dichloroethane, 2-Methoxyethanol, Acetic Acid, Triuoroacetic Acid
Low Chloroform, Dichloromethane, Carbon Tetrachloride, 1,4-Dioxane, THF, Glyme, and other ethers, Ethyl
Acetate, Pyridine, Triethylamine, Toluene, Benzene, Chlorobenzene, Xylenes, Pentane, Hexane and other
hydrocarbons
Minimum Cavity Load
A minimum cavity load must be met before running a microwave method. The minimum cavity load is determined
by the solvent, number of vessels, and vessel type: GlassChem 20, EasyPrep, EasyPrep Plus, and Open Vessel.
Microwave Absorbency GlassChem 20 EasyPrep Plus Open Vessel
Low 50 mL 50 mL 100 mL
Medium 50 mL 50 mL 100 mL
High 10 mL 20 mL 100 mL
Microwave Safeguards
• Never heat liquids in a sealed vessel or container that is not equipped with a pressure relief device.
• Cover all solids in the reaction vessel with liquid
• Metal catalysts can be used, but ensure they are wetted or in solution
• Finely divided (powder) metals are safer than bulk metals for heterogeneous catalysis
• Solid state reactions should not be performed in a Mars 6
• Never exceed the maximum working volume of the vessel
• Always use a stir bar that adequately mixes the reaction contents in the microwave
• When transitioning a conventional, open vessel reaction to a closed vessel reaction, Increase reaction
temperature 25 °C above the highest boiling point solvent in vessel
• Always use the Ramp-to-Temperature control type and allow for sufcient time to heat to temperature, especially
for low absorbing solvents. This will help prolong the life of the magnetron and microwave unit.
• Start with the recommended power based on the number and type of vessels used
• Always prepare the Control (vessel with ber optic probe) the same as the Standard vessels
• The Control vessel must contain the same solvent and reagents as used in the Standard vessels
• Always distribute multiple vessels evenly around the turntable
