Photochemical Reactors

Preparative methods using ultraviolet and visible radiation in place of heat enable chemical compounds to be synthesized often by novel reactions with high yields and in the absence of side reactions. Of the major reactions in organic photochemistry, photodissociation is a convenient source of reactive intermediates (e.g. benzyne, carbenes) often produced following extrusion of small molecules such as SO2, CO2, or N2. Photoaddition is well represented by photochemical Diels-Alder reaction; photocyclic rearrangements have opened up the extensive field of intramolecular cyclisation reactions of cyclic polyenes and the ingenious production of 'cage' structures; photochemical substitutions have provided routes to isomers of substituted benzenoid compounds difficult to make by thermal procedures and photo-oxidation and photo-reduction allow molecules to incorporate molecular oxygen or hydrogen.