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The 3,5‐dinitroanilide anion: a singlet anilide anion with evidence for a thermally accessible triplet state
Author(s) -
Perrotta Raffaele R.,
Falvey Daniel E.
Publication year - 2013
Publication title -
journal of physical organic chemistry
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.325
H-Index - 66
eISSN - 1099-1395
pISSN - 0894-3230
DOI - 10.1002/poc.3118
Subject(s) - chemistry , singlet state , ion , deprotonation , density functional theory , counterion , triplet state , photochemistry , computational chemistry , singlet fission , molecule , atomic physics , excited state , organic chemistry , physics
Anilide anions derived from deprotonation of 4‐nitroaniline and 3,5‐dinitroaniline were examined by using DFT calculations, as well as ultraviolet and 1 H NMR experiments. The calculations indicate that the free anions are ground state singlets. However, when coordinated to a Li counterion, the 3,5‐dinitroanilide anion is predicted to have a very narrow gap between the singlet and the triplet state. Spectroscopic data is consistent with this prediction. The UV–Vis spectrum of this anion shows a maximum absorbance at approximately 310 nm, which is in reasonable agreement with the spectrum for the singlet anion calculated by time‐dependent density functional theory. On the other hand, NMR peak broadening and a modest Evans shift are consistent with the thermal population of a small amount of triplet anion. Copyright © 2013 John Wiley & Sons, Ltd.