Simultaneous electrochemical and electron paramagnetic resonance studies of fullerene anion radicals C 60 1− and C 60 3−

Abstract

Abstraer. Simultaneous electrochemical and electron paramagnetic resonance experiments have been carried out on the reduced C60 fullerene to examine the g-factor assignment of the radical species. C~o and C630 -show the following EPR characteristics at room temperature: C~0-: gl = 2.0002+0.0001, 2ABls = 0.17 mT, and C~0-: g3-= 2.0008_+0.0001, 2ABIs = 0.07 mT. EPR linewidths are apparently narrower compared to those in most of the speetra previously reported. Variable temperature EPR study on solution containing C610 -has shown that gl-value is not while the linewidth is only slightly temperature dependent.

EPR of a fullerene-molecule-derived paramagnetic center as a mesoscopic conducting object

“…Assuming that the C 60 molecule is a mesoscopic object, electron delocalization and metallic conductivity on the graphitelike surface can be regarded as being 9 2.0030 H^ 0 C Ie 4 0 0 Csó Collected experimental EPR data of g-factor for fullerene ions [17,18,[22][23][24]. The solid parabola describes the energy of the charged state in C bo , T -(-v -1.49)2 after Pederson and Quong [8] and can be correlated to the g-factor value of Cóo centers.…”

“…According to Norman [14], due to the bond deformation on the C 60 carbon skeleton the g-value for C60 should be shifted downwards from go = 2.0023. In fact, the C center has a g-factor of g = 1.9997 both in the solid state [ 17] and in solution [18]. The increase in the anion valency v of C leads to the increase of the g-factor value.…”

“…The experimental data on g-factor [17,18,[22][23][24] vs. valence state can be correlated to the theoretical energy dependence on the charge transfer transition in C60 molecule (Fig. 5) T -(-v -1.49) 2 calculated by Pederson and Quong [8].…”