Mechanistic studies of oxidation reactions by fluorescence spectroscopy: a critical assessment

The synthesis and properties of a ratiometric fluorescent dye system as a probe for the detection of oxidizing species are described. The dye consists of a strongly fluorescent Bodipy label attached to a styryl moiety. The oxidation of the exocyclic double bond by agents for syn‐ and anti‐ dihydroxylation leads to a visible change in fluorescence colour from orange to green. IR spectroscopy provides evidence for the generation of the epoxide in the reaction with peroxides, whereas a ketone and a product of unknown structure are produced in the reaction with osmiumtetroxide, each in contrast to the expected hydroxylations. Based on these first attempts, we discuss the significance of fluorescence spectroscopy to track chemical reactions at low concentrations and give a perspective of how present shortcomings can be overcome. Copyright © 2009 John Wiley & Sons, Ltd.