Instrument overview / 1
Instrument Overview
PETwave
The CEM PETwave™ is designed to enhance the ability to perform chemical reactions under controlled conditions
on a small scale inside a ‘hot’ cell or glove box. The system facilitates solution phase chemistry, solvent
evaporation to concentrate reactants and hydrolysis to remove protecting groups. It accommodates conical shaped
vessels ranging in working volume from 50 µL to 2.5 mL. Primary uses of the PETwave™ are for radiolabeling
chemistry in a ‘hot’ cell or chemistry in the controlled environment of a glove box.
Microwave
Microwave energy is applied to the vessel contents (reactants, catalysts, salts, solvents) to accelerate the
chemical reaction. The microwave absorption properties of some liquid and solid materials, due to their polar and
ionic characteristics, have the capability to signicantly enhance chemical reactions relative to traditional energy
application (heating) techniques. The microwave interaction properties with the reactants, intermediates, catalysts,
and salts provide unique opportunities for the synthetic chemist. Power is programmable in 1 watt increments from
0 to 100 watts.
Stirring
Stirring is accomplished using electromagnetic stirring plates located beneath the cavity in conjunction with stir
bars placed in the reaction vessel; ensuring a homogeneous sample. The stir bars must be Teon® coated iron
oxide bars. When placed in the microwave eld, the iron oxide bars will reect the microwave energy without
damaging the instrument. Stirring can be programed as off, low medium or high.
WARNING
If the instrument is suspected of interfering with the operation of a pacemaker, the instrument should be
turned off or the pacemaker wearer should move away from the instrument.
Temperature
Temperature is measured by an Infrared Control System. This temperature control system uses a non-contact,
infrared sensor located below the microwave cavity oor. The sensor is vessel volume independent and is used in
a feedback loop with the on-board computer to control the temperature rise rate and control point of the vessel
contents. Temperature is programmable from room temperature to 300oC.
Cooling
Cooling – The cooling feature consists of necessary solenoid valves and ports to direct a cooling gas (either
nitrogen or “clean” air) onto the outside wall of the reaction vessel. This provides the ability to rapidly cool
(quench) a reaction after the application of microwave energy. Cooling is programmable as on or off and may be
adjusted using the regulator up to 60 psi.
Pressure
Reactions are performed at or below boiling point of the solvent; therefore, reactions may only performed at
ambient/atmospheric pressure.