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Isolating Free Carbenes, their Mixed Dimers and Organic Radicals
Published on: April 19, 2019
Modular Synthesis of Rigid Polyacene Dimers for Singlet Fission
Thomas J Carey1, Ethan G Miller1, Alexander T Gilligan1
1Department of Chemistry and Biochemistry, University of Colorado Boulder , Boulder, Colorado 80309, United States.
Abstract:
An improved, modular synthesis of rigid, geometrically well-defined, alkyne-substituted tetracene (1) and pentacene (2) dimers is reported. The synthesis is rooted in sequential Diels-Alder reactions of a norbornyl tetraene with triisopropylsilylacetylene-substituted (TIPS-acetylene) quinone dienophiles. The incorporation of solubilizing and stabilizing TIPS-acetylene groups early in the synthesis affords a mild and reliable route, providing access, for the first time, to norbornyl-bridged pentacene dimers. A preliminary exploration of the excited state behavior of these molecules is also described.
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