STABILITIES AND REACTIVITIES OF BUCKMINSTERFULLERENE RADICALS, (BU(T)O)(N)C-60(CENTER-DOT), TOWARDS DIOXYGEN, NITRIC-OXIDE AND SPIN-TRAPPING AGENTS

(Bu(t)O)(n)C-60(.) radicals have been conveniently produced by additio n of photochemically generated Bu(t)O(.) radicals to buckminsterfuller ene (C-60). Radical adducts (where n > 2) are very persistent under N- 2 at room temperature and can be observed for as long as nine days. Re actions between the radical adducts and dioxygen (O-2) are slow and re activities vary among (Bu(t)O)(n)C-60(.) radicals, However, nitric oxi de ((NO)-N-.) reacts more rapidly with (Bu(t)O)(n)C-60(.) radicals. Am ong the product components are stable dibuckminsterfullerene aminoxyl (nitroxide) radicals, [(Bu(t)O)(n)C-60]N-2-O-., which have been observ ed by EPR spectroscopy at concentrations of ca, 10(-7) M for the first time. Surprisingly, (Bu(t)O)(n)C-60(.) radicals are not reactive towa rds several typical radical-trapping agents (spin traps), e.g. DMPO (5 ,5-dimethyl-1-pyrroline N-oxide), PEN (C-phenyl N-tert-butylnitrone da gger), NB (nitrosobenzene) and MNP (2-methyl-2-nitrosopropane), when u sed at typical concentrations (10-100 mM) at room temperature.