Indirect 1H NMR characterization of H2@C60 nitroxide derivatives and their nuclear spin relaxation
作者:Yongjun Li、Xuegong Lei、Xia Li、Ronald G. Lawler、Yasujiro Murata、Koichi Komatsu、Nicholas J. Turro
DOI:10.1039/c1cc15149e
日期:——
(1)H NMR of two H(2)@C(60) nitroxide derivatives has been characterized indirectly by reducing to their corresponding hydroxylamines. Nuclear spin relaxation of the endohedral H(2) and external protons of the H(2)@C(60) nitroxide and its corresponding hydroxylamine were measured and analyzed. The observed spectra are consistent with negligible scalar coupling between the unpaired electron and the endo-H(2)
group 2,2,6,6-tetramethylpiperidine-1-oxyl have been synthesized. A detailed EPR and ENDOR study of the neutral radicals and of their reduction products is reported. All the neutral species give EPR spectra consisting of a main triplet of lines with = 15 G splitting by the sup 14}N nucleus, typical of nitroxide radicals. Some of them show additional well-resolved splittings by methyl and methylene