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Updated: May 18, 2026

Using Cyclic Voltammetry, UV-Vis-NIR, and EPR Spectroelectrochemistry to Analyze Organic Compounds
Published on: October 18, 2018
Time resolved EPR of [70]fullerene monoadducts in the photoexcited triplet state
Lorenzo Franco1, Antonio Toffoletti, Michele Maggini
1Dipartimento di Scienze Chimiche, Università di Padova, Italy. lorenzo.franco@unipd.it
Abstract:
Triplet excited states of isomers α, β and γ of N-methyl-[70]fulleropyrrolidine in glassy toluene (T = 120 K) are investigated with Time Resolved EPR (TR-EPR) spectroscopy using pulsed laser photoexcitation. Both the zero field splitting (ZFS) parameters D, E and the anisotropic triplet population rates are measured. Results reveal a strong dependence of the triplet state wavefunction on the position (α, β or γ) of the pyrrolidine addend with respect to the pole of the [70]fullerene unit. The relevant molecular orbitals have been calculated giving support to this finding. The dipolar tensor principal axes are located at the molecular reference frame from the inspection of the EPR spectra in a frozen liquid crystal (E7). Time evolution of the triplet EPR signals is different among the isomers, suggesting different triplet lifetimes and/or spin relaxation properties. The spin-density distribution in the first triplet state for N-methyl-[70]fulleropyrrolidine is compared with that previously observed for pristine C(70).
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