An easy and inexpensive flash spectroscopy experiment

In this work we applied a flash photolysis technique to the study of the kinetic behavior of a synthetic flavylium salt in aqueous solution. The kinetic processes triggered by the light pulse of a common camera flash, are followed by means of a sligthly modified, computer controlled, spectrophotometer. Light induces reversible absorbance changes and two different transient species are evidenced prior the full recovery of the system. The kinetic behavior and the spectra of the transient species are reported. The proposed experiment is cheap and easy and allows students of all levels to become familiar with the concepts of transient decay kinetics and time resolved spectra.