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[DPEPhosbcpCu]PF6: A General and Broadly Applicable Copper-Based Photoredox Catalyst
Published on: May 21, 2019
Cascade Photoreaction in Crystals: A Phase Change Caused by a Dewar Benzene Quantum Chain Triggers a Topochemical [2
Indrajit Paul1, Krzysztof A Konieczny1,2, Roberto Chavez1
1Department of Chemistry and Biochemistry, University of California, Los Angeles, California 90095-1569, United States.
Abstract:
Crystals undergoing tandem reactions where the first transformation enables the second one are rare. Using photoreactive Dewar benzene 3,4,5,6-tetramethyl-1,2-dicarboxylic diacid (DB) as a hydrogen-bonding template for the [2π+2π] photodimerization of trans-4,4'-bipyridyl-ethenes (BPE), we obtained crystals DB-BPE-NT with a DB:BPE = 2:1 stoichiometry with double bonds at a nonreactive distance of 5.957 Å. Exposure to UV light resulted in valence bond isomerization to Hückel benzene 3,4,5,6-tetramethyl-1,2-dicarboxylic acid (HB) by a quantum chain reaction that triggered the sought-after topochemical [2π+2π] photodimerization reaction. Notably, crystals HB:BPE-T with the Hückel benzene isomer and BPE adopted a 2:2 stoichiometry and displayed an efficient topochemically templated photodimerization reaction.
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