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Evidence for a Transition Between Singlet and Triplet States in the Electrochemical Reduction of 2,2′‐4,4′‐Tetranitrobiphenyl
Author(s) -
Gallardo Iluminada,
Guirado Gonzalo,
Marquet Jordi,
Moreno Miquel
Publication year - 2001
Publication title -
chemphyschem
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.016
H-Index - 140
eISSN - 1439-7641
pISSN - 1439-4235
DOI - 10.1002/1439-7641(20011217)2:12<754::aid-cphc754>3.0.co;2-u
Subject(s) - singlet state , electron paramagnetic resonance , chemistry , triplet state , photochemistry , electrochemistry , gas phase , singlet fission , computational chemistry , crystallography , molecule , excited state , atomic physics , nuclear magnetic resonance , organic chemistry , physics , electrode
Two different dianionic species , close in energy, result from the electroreduction of 2,2′‐4,4′‐tetranitrobiphenyl, 1 . The first‐formed species has biradical characteristics, such as a triplet EPR spectrum, but it slowly evolves to another EPR‐silent species, essentially described as a quinoid form. DFT calculations also support the existence of two dianionic states of the dianion, singlet and triplet, differing by less than 10 kcal mol −1 (in the gas phase); the quinoid singlet state is more stable.