Open AccessSpin Signature of the C60 Fullerene Anion: A Combined X- and D-Band EPR and DFT Study
Author(s) -
Jens Niklas,
Kristy L. Mardis,
Oleg G. Poluektov
Publication year - 2018
Publication title -
the journal of physical chemistry letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.563
H-Index - 203
ISSN - 1948-7185
DOI - 10.1021/acs.jpclett.8b01613
Subject(s) - electron paramagnetic resonance , fullerene , density functional theory , ion , materials science , relaxation (psychology) , anisotropy , spectroscopy , annealing (glass) , chemical physics , molecular physics , condensed matter physics , nuclear magnetic resonance , chemistry , computational chemistry , physics , psychology , social psychology , organic chemistry , quantum mechanics , composite material
Fullerenes attract much attention in various scientific fields, but their electronic properties are still not completely understood. Here we report on a combined EPR and DFT study of the fullerene anion C 60 - in solid glassy environment. DFT calculations were used to characterize its electronic structure through spin density distribution and magnetic resonance parameters. The electron spin density is not uniformly distributed throughout the C 60 - cage but shows a pattern similar to PC 61 BM - . EPR spectroscopy reveals a rhombic g-tensor sensitive to the environment in the frozen glassy solutions, which can be rationalized by deformation of the fullerenes along low-frequency vibrational modes upon cooling. DFT modeling confirms that these deformations lead to variation in the C 60 - g values. The decrease in g-tensor anisotropy with sample annealing is related to the lessening of g-tensor strain upon temperature relaxation of the most distorted sites in the glassy state.