EPR Spectroscopy of Radical Ions of a 2,3-Diamino-1,4-naphthoquinone Derivative

0490380 - ÚOCHB 2019 RIV US eng J - Článek v odborném periodiku
Tarábek, Ján - Wen, Jin - Dron, P. I. - Pospíšil, Lubomír - Michl, Josef
EPR Spectroscopy of Radical Ions of a 2,3-Diamino-1,4-naphthoquinone Derivative.
Journal of Organic Chemistry. Roč. 83, č. 10 (2018), s. 5474-5479. ISSN 0022-3263. E-ISSN 1520-6904
Grant CEP: GA ČR GA15-19143S
Institucionální podpora: RVO:61388963
Klíčová slova: singlet fission * energies * model
Obor OECD: Organic chemistry
Impakt faktor: 4.745, rok: 2018

We report the electron paramagnetic resonance spectra of the radical cation and radical anion of 1,2,2,3-tetramethy1-2,3-dihydro-1H-naphtho-[2,3-d]-imidazole-4,9-dione (1) and its doubly C-13 labeled analogue 2, of interest for singlet fission. The hyperfine coupling constants are in excellent agreement with density functional theory calculations and establish the structures beyond doubt. Unlike the radical cation 1(.+), the radical anion 1(.-) and its parent 1 have pyramidalized nitrogen atoms and inequivalent methyl groups 15 and 16, in agreement with the calculations. The distinction is particularly clear with the labeled analogue 2(.-).
Trvalý link: http://hdl.handle.net/11104/0284626