Microwave photochemical reactor

The microwave photochemical reactor is an essential tool for experimental work in this field. Such equipment enables simultaneous irradiation of the sample with both MW and UV/VIS radiation. The idea of using an electrodeless lamp (EDL), in which the discharge is powered by the MW field, for photochemistry was bom half a century ago [46, 68]. The lamp was originally proposed as a source of UV radiation only,... 

Kl4n, P., H4jek, M. and Cirkva, V., The electrodeless discharge lamp a prospective tool for photochemistry, Part 3 the microwave photochemistry reactor, /. Photochem. Photobiol, A Chem., 2001, 140, 185. 

Klan, P. Hajek, M., Cirkva, V., The Electrodeless Discharge Lamp a Prospective Tool for Photochemistry. Part 3. The Microwave Photochemistry Reactor, J. Photochem. Photobiol. A 2001, 140, 185 189. 

As the energy intensity of a process becomes more of an issue on cost and environmental grounds we shall start to see processes being developed using microwave, ultrasonic, electrochemical and photochemical reactors. For some reactions these techniques will not only deliver energy efficiency but may also lead to higher selectivities and atom efficiencies. 

Chemat and his coworkers [92] have proposed an innovative MW-UV combined reactor (Fig. 14.7) based on the construction of a commercially available MW reactor, the Synthewave 402 (Prolabo) [9[. It is a monomode microwave oven cavity operating at 2.45 GHz designed for both solvent and dry media reactions. A sample in the quartz reaction vessel could be magnetically stirred and its temperature was monitored by means of an IR pyrometer. The reaction systems were irradiated from an external source of UV radiation (a 240-W medium-pressure mercury lamp). Similar photochemical applications in a Synthewave reactor using either an external or internal UV source have been reported by Louerat and Loupy [93],... 

Gunning, Pertel, and their coworkers reported the photochemical separation of mercury isotopes [92-95] in a flow reactor which consisted of a microwave-operated discharge lamp [52, 96] cooled by a flowing film of water. A filter cell and a circulation system, to prevent heating of the filter solution and the cell, were placed concentrically and coaxially with the lamp. A similar reactor, for small-scale laboratory photolysis of organic compounds in the solution or gas phase, has been proposed by Den Besten and Tracy [91]. In this arrangement the EDL was placed in a reaction solution and was operated by means of an external microwave field from a radio or microwave-frequency transmitter (Fig. 19.11). The quantum output of the lamp was controlled by changing the output of the trans-... 

In this chapter we report and analyze examples of asymmetric organocatalytic reactions under non-classical conditions high pressure, microwave heating, ultrasound irradiation, and ball milling. Organocatalytic processes based on photochemical or electrochemical activation as well as applying continuous-flow reactors are not included. 

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