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Updated: Jan 4, 2026

Atom Transfer Radical Polymerization of Functionalized Vinyl Monomers Using Perylene as a Visible Light Photocatalyst
Published on: April 22, 2016
Two-electron transfer stabilized by excited-state aromatization
Jinseok Kim1, Juwon Oh1, Seongchul Park2
1Spectroscopy Laboratory for Functional π-electronic Systems and Department of Chemistry, Yonsei University, Seoul, 03722, Korea.
Abstract:
The scientific significance of excited-state aromaticity concerns with the elucidation of processes and properties in the excited states. Here, we focus on TMTQ, an oligomer composed of a central 1,6-methano[10]annulene and 5-dicyanomethyl-thiophene peripheries (acceptor-donor-acceptor system), and investigate a two-electron transfer process dominantly stabilized by an aromatization in the low-energy lying excited state. Our spectroscopic measurements quantitatively observe the shift of two π-electrons between donor and acceptors. It is revealed that this two-electron transfer process accompanies the excited-state aromatization, producing a Baird aromatic 8π core annulene in TMTQ. Biradical character on each terminal dicyanomethylene group of TMTQ allows a pseudo triplet-like configuration on the 8π core annulene with multiexcitonic nature, which stabilizes the energetically unfavorable two-charge separated state by the formation of Baird aromatic core annulene. This finding provides a comprehensive understanding of the role of excited-state aromaticity and insight to designing functional photoactive materials.
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