Visible Light Photocatalysis of 6π Heterocyclization

Photo‐mediated 6π cyclization is a valuable method for the formation of fused heterocyclic systems. Here we demonstrate that irradiation of cyclic 2‐aryloxyketones with blue LED light in the presence of an Ir^III complex leads to efficient and high yielding arylation across a panoply of substrates by energy transfer. 2‐Arylthioketones and 2‐arylaminoketones also cyclize effectively under these conditions. Quantum calculation demonstrates that the reaction proceeds via conrotatory ring closure in the triplet excited state. Subsequent suprafacial 1,4‐hydrogen shift and epimerization leads to the observed cis‐fused products.     

Energy Transfer between Spatially Separated Entangled Molecules

Light–matter strong coupling allows for the possibility of entangling the wave functions of different molecules through the light field. We hereby present direct evidence of non‐radiative energy transfer well beyond the Förster limit for spatially separated donor and acceptor cyanine dyes strongly coupled to a cavity. The transient dynamics and the static spectra show an energy transfer efficiency approaching 37 % for donor–acceptor distances ≥100 nm. In such systems, the energy transfer process becomes independent of distance as long as the coupling strength is maintained. This is consistent with the entangled and delocalized nature of the polaritonic states.