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Dinitreno pentaradicals: organic sextet molecules
Author(s) -
MieresPérez Joel,
Henkel Stefan,
MendezVega Enrique,
Schleif Tim,
Lohmiller Thomas,
Savitsky Anton,
Sander Wolfram
Publication year - 2017
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.3621
Subject(s) - chemistry , nitrene , electron paramagnetic resonance , molecule , radical , spectroscopy , photochemistry , photodissociation , ground state , oxygen , triplet state , crystallography , nuclear magnetic resonance , atomic physics , organic chemistry , catalysis , physics , quantum mechanics
A new sextet ground state molecule, the 2,4,6‐trichloro‐1,3‐dinitrenophenoxyl radical, was obtained upon UV photolysis of the corresponding diazido precursor in argon at 5 K. The sextet molecule is formed stepwise with the triplet nitrene, the quartet nitreno radical, and the quintet dinitrene as intermediates that were detected by EPR spectroscopy. IR and UV–Vis measurements only allowed us to observe the main product, the quintet dinitrene. The coupling between the two nitrene centers and the oxygen centered radical in the sextet state results in zero‐field splitting (zfs) parameters of |D/hc| = 0.088 cm −1 and |E/hc| = 0.009 cm −1 , considerably larger than in previously reported organic sextet molecules. An analogous sextet dinitrene formed by replacing the oxygen centered radical by a carbon centered radical was also studied by EPR spectroscopy, and in this case the zfs parameters |D/hc| = 0.125 cm −1 and |E/hc| = 0.023 cm −1 indicate even larger spin localization. Copyright © 2016 John Wiley & Sons, Ltd.