Photochemical Flow Reactions

The versatility of photochemical flow processes is rapidly expanding, and we suggest that this technique is capable of broadening the general appeal and impact of photochemistry similar or even to a greater extent to what microwave technology has done to thermal processes. This review highlights the recent developments that support this suggestion as well as the technological challenges that have yet to be resolved. Continuous photoflow reactions allow for better control over heating and mixing, are safer to operate on scale-up, in particular if LEDs are used in place of Hg lamps, they offer a higher surface/volume ratio and more efficient light penetration than batch mode photoreactions, and furthermore allow for the removal of products in-line to avoid secondary decompositions and poor conversions.