A Strategy for the Detection of Diels–Alder Reactions Using Fluorescence Quenching of Conjugated Polymers

Abstract

AbstractA new method has been developed to detect the formation of carbon–carbon bonds by Diels–Alder reactions based on the fluorescence quenching of conjugated polymers. Conjugated copolymers containing various amounts of functional furan pendant groups (PFP–F) have been synthesized and characterized. A maleimide group linked to 1‐methyl‐4,4‐bipyridinium iodide acts as the electron quencher (M–MV2+). The Diels–Alder reaction between the maleimide and furan moieties results in intramolecular electron transfer from the conjugated copolymer to the MV2+, and thus the fluorescence of the conjugated copolymer is quenched via a photoinduced electron transfer process. Higher furan concentrations increase the fluorescence quenching efficiency (EF) of the conjugated copolymers. The copolymer PFP–F3 with the highest furan content can be used as a platform to monitor Diels–Alder reactions. The PFP–F3/M–MV2+system can also be used to screen catalysts for Diels–Alder reactions.