6533b872fe1ef96bd12d3844
RESEARCH PRODUCT
Breaking the semi-quinoid structure: spin-switching from strongly coupled singlet to polarized triplet state.
E. V. GorelikYoshio TekiMartin BaumgartenPrince RavatYoshikazu Itosubject
ChemistryOrganic ChemistrySpin transitionGeneral ChemistryMolecular physicsCatalysislaw.inventionPhotoexcitationlawComputational chemistryIntramolecular forceSinglet stateTriplet stateElectron paramagnetic resonanceSpin (physics)Spectroscopydescription
2,7-TMPNO (4,5,9,10-tetramethoxypyrene-2,7-bis(tert-butylnitroxide)) was found to exist in semi-quinoid form with unprecedented strong intramolecular magnetic exchange interaction of 2 J/kB = 1185 K operating over a distance of 10 A. Structural transformations with the activation energy of ΔEeq = 949 K were observed by varying the temperature, from more quinoid structure at low temperature to more biradicaloid structure at higher temperature. Moreover, this molecule undergoes a transient spin transition from singlet to polarized triplet state upon photoexcitation revealed by TREPR spectroscopy. The spin Hamiltonian parameters were determined to be S = 1, g = 2.0065, D = -0.0112 cm(-1), and E = -0.0014 cm(-1) by spectral simulation with the hybrid Eigenfield/exact diagonalization method.
| year | journal | country | edition | language |
|---|---|---|---|---|
| 2014-07-31 | Chemistry (Weinheim an der Bergstrasse, Germany) |