A new stable pyrrolidine functionalized fullerene derivative, C69H10N2O2, has been synthesized, purified by high performance liquid chromatography, and characterized by MALDI mass spectrometry, UV-vis spectroscopy, Fourier transform infrared, H-1 and C-13 nuclear magnetic resonance. The magnetic properties of the analogous endohedral species have been studied by both continuous wave (CW) and pulsed EPR. CW-EPR spectra indicated an anisotropic hyperfine interaction and a permanent zero-field-splitting (ZFS). Both CW and pulsed EPR showed the ZFS parameter D-eff to be around 17 MHz. Pulsed EPR revealed a biexponential decay in both T-1 and T-2, yielding a molecular tumbling correlation time tau(c) of 31.4 +/- 2.5 ps. (c) 2006 Elsevier B.V. All rights reserved.