2014 marked the 50th anniversary of the start of the IUPAC Symposium on Photochemistry. This, the XXVth edition, was held in Bordeaux, France from 13th to 18th July 2014 and welcomed over 600 participants from all five continents. The research, which was presented through 118 lectures and 365 posters, represented every discipline of the photochemical sciences, ranging from fundamental aspects to more applied research dealing with societal objectives, concerning environmental and sustainable energy issues. More specifically, topics represented include supramolecular photochemistry, nanomaterials and nanotechnology, ultrafast spectroscopies and processes, fluorescence imaging, photochromism, photochemical transformations and biological photochemistry. It is noteworthy that most of these areas were unknown when the original meetings were held and show how matter–light interactions have intrigued several generations of researchers from different disciplines, and evolved from a niche topic to a central pillar of modern research.
Several of the wide ranging topics are represented in this eclectic issue and a subsequent issue of Pure and Applied Chemistry, through contributions of some plenary and invited speakers at the Bordeaux meeting. Contributions from prize winners include Porter Medal winner Masahiro Irie, who was rewarded for his outstanding contribution to photochromism, and Norbert Hoffman who described mechanistic photochemistry involving furanones. Additionally, on this auspicious occasion, an overview of the evolution of the conference series and enduring memories from participant Silvia Braslavsky is given in the second issue dedicated to the conference.
The high quality of contributions from the ensemble of the participants and an ever increasing number of dynamic early stage researchers bode well for subsequent IUPAC Photochemistry symposia and the discipline as a whole. We hope you enjoy this series of articles.