Journal ArticleQuantum chain amplification in nanocrystalline Dewar benzenes by intramolecular sensitizationRivera, Edris; Paul, Indrajit; Fajardo, Javier; Garcia-Garibay, Miguel AnanaQuantum chain reactions are characterized by the formation of several photoproducts per photon absorbed (FQC > 1) and constitute a promising signal amplification mechanism. The triplet-sensitized isomerization of Dewar benzene is known to undergo quantum chain reactions characterized by an adiabatic valence-bond isomerization to the excited state of Hückel benzene, which is able to transfer its triplet energy to a new ground state Dewar benzene that reacts to continue the chain. Given that diffusion-mediated energy transfer is the chain-limiting event in solution, we demonstrate here that reactions in crystals are significantly more efficient by taking advantage of energy transfer by a presumed exciton delocalization mechanism. Using Dewar benzenes with covalently attached, high energy triplet sensitizers we have demonstrated the efficiency of the solid state by the amplification of a quantum yield of ca. FQC ≈ 76 in acetonitrile solution to as much as ca. FQC ≈ 100–120 in submicron size specimens prepared by the re-precipitation method, and up to ca. FQC ≈ 300 with microcrystalline powders suspended in water.Royal Society of Chemistry2023-05-3110633236Chemical Science14215802 to 58102041-6520https://doi.org/10.1039/D3SC01074K2154210Quantum chain reactions, solid state photochemistry4.5MBpdfNational Science Foundation