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Site Directed Spin Labeling and EPR Spectroscopic Studies of Pentameric Ligand-Gated Ion Channels
Published on: July 4, 2016
High-spin to low-spin relaxation kinetics in the [Fe(TRIM)2]Cl2 complex
Sébastien Bonhommeau1, Nicolas Bréfuel, Villö K Pálfi
1Laboratoire de Chimie de Coordination, UPR 8241 CNRS, 205 route de Narbonne, F-31077, Toulouse Cedex, France.
Abstract:
A quasi-quantitative photo-induced low-spin (LS)-->high-spin (HS) conversion of FeII ions has been observed in the [Fe(TRIM)2]Cl2 complex by irradiating the sample with blue light (488 nm) at 10 K. The time dependence of the HS-->LS relaxation has been studied between 10 K and 44 K by means of magnetic susceptibility measurements. These relaxation curves could be satisfactorily fitted by mono-exponential decays including tunnelling effect except for temperatures below 30 K. The introduction of a distribution of vibrational frequencies into this model improved significantly the fits in the low-temperature range and gave a good agreement with the experimental data in the whole temperature range suggesting a multi-rate relaxation process in this complex.
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