On the design of a flexible, accessible photoreactor to pilot flow photochemistry experiments

Abstract “A beaker, in a beaker, in a bucket” – a tuneable photoreactor system that can be rapidly assembled from readily available components is detailed. Involving interchangeable reaction coils and LED light sources, the system is designed to be accessible and affordable, allowing chemists to employ the well documented benefits of (flow) photochemistry to obtain proof-of-concept, without requiring investment in commercial equipment or in house fabrication of components. The flow photoreactor system, which can also be employed for batch reactions, has been characterised, and the visible light (460 nm) isomerisation of trans - to cis -stilbene, employing Ir(ppy) 3 as a photosensitiser, has been used as a model reaction to evaluate its performance. It was found that the photostationary state of this reaction could be achieved within just 2 min of irradiation in flow with a 20 mW cm − 2 light source, allowing for reactor throughputs as high as 0.5 mmol min − 1 , demonstrating the utility of this easy to access system.