PMID- 21339084
OWN - NLM
STAT- MEDLINE
DCOM- 20110719
LR  - 20110328
IS  - 1873-3557 (Electronic)
IS  - 1386-1425 (Linking)
VI  - 78
IP  - 5
DP  - 2011 May
TI  - Effects of spin transitions degeneracy in pulsed EPR of the fullerene C70 triplet 
      state produced by continuous light illumination.
PG  - 1548-52
LID - 10.1016/j.saa.2011.01.047 [doi]
AB  - X-band echo-detected electron paramagnetic resonance (ED EPR) spectra of triplet 
      state of fullerene C(70) generated by continuous light illumination were found to 
      correspond below 30K to a non-equilibrium electron spin polarization. Above 30K 
      spectra are characteristic of Boltzmann equilibrium. Spectra were simulated 
      fairly well with zero-field splitting parameters D=153 MHz and E and distributed 
      within the range of 6-42 MHz. The origin of E distribution is attributed to the 
      Jahn-Teller effect, which in glassy matrix is expected to depend on the local 
      surrounding of a fullerene molecule (a so-called E-strain). In the center of ED 
      EPR spectra a narrow hole was observed. With increase of the microwave pulse 
      turning angle this hole transforms into a single narrow absorptive line. 
      Numerical simulations by density matrix formalism confirm that central hole 
      originates from a simultaneous excitation of both allowed electron spin 
      transitions of the triplet (T(0)<-->T(+) and T(0)<-->T(-)), because of their degeneracy 
      at this spectral position. Also explanations are given why this hole has not been 
      observed in the previously reported experiments on continuous wave EPR and on ED 
      EPR under laser pulse excitation.
CI  - Copyright (c) 2011 Elsevier B.V. All rights reserved.
FAU - Uvarov, Mikhail N
AU  - Uvarov MN
AD  - Institute of Chemical Kinetics and Combustion, Novosibirsk, Russia.
FAU - Kulik, Leonid V
AU  - Kulik LV
FAU - Pichugina, Tatiana I
AU  - Pichugina TI
FAU - Dzuba, Sergei A
AU  - Dzuba SA
LA  - eng
PT  - Journal Article
PT  - Research Support, Non-U.S. Gov't
DEP - 20110202
PL  - England
TA  - Spectrochim Acta A Mol Biomol Spectrosc
JT  - Spectrochimica acta. Part A, Molecular and biomolecular spectroscopy
JID - 9602533
RN  - 0 (Fullerenes)
RN  - 0 (Spin Labels)
RN  - 115383-22-7 (fullerene C70)
SB  - IM
MH  - Computer Simulation
MH  - Electron Spin Resonance Spectroscopy
MH  - Fullerenes/*chemistry
MH  - *Light
MH  - *Spin Labels
MH  - Time Factors
EDAT- 2011/02/23 06:00
MHDA- 2011/07/20 06:00
CRDT- 2011/02/23 06:00
PHST- 2010/10/06 00:00 [received]
PHST- 2010/12/23 00:00 [revised]
PHST- 2011/01/26 00:00 [accepted]
PHST- 2011/02/23 06:00 [entrez]
PHST- 2011/02/23 06:00 [pubmed]
PHST- 2011/07/20 06:00 [medline]
AID - S1386-1425(11)00074-6 [pii]
AID - 10.1016/j.saa.2011.01.047 [doi]
PST - ppublish
SO  - Spectrochim Acta A Mol Biomol Spectrosc. 2011 May;78(5):1548-52. doi: 
      10.1016/j.saa.2011.01.047. Epub 2011 Feb 2.