Multifrequency CW EPR Spectroscopy of Extraterrestrial Carbonaceous Matter

摘要: In this work, the carbonaceous matter of Orgueil, Murchison and Tagish Lake meteorites anda reference coal is studied by multifrequency continuous-wave electron paramagnetie resonance (EPR) spectroscopy from 4 to 285 GHz. It found that shape EPR line radicals in meteoritic Lorentzian all frequency range, while only below 95 GHz becomes inhomogeneously broadened at higher frequency, as previously observed for coals other authors. ThŸ points strong exchange interac- tions matter, resulting a pronounced spin clustering does not occur biogenic (eoals). The temperature dependence width has been detail X- W-bands Orgueil meteorite. Ir confirmed our previous model presence with thermally accessible triplet states (TATS) meteorites. These TATS, which were attributed diradicaloids moieties on basis molecular quantum DFT cal- culations (L. Binet, D. Gourier, S. Derenne, F. Robert, I. Ciofini: Geochim. Cosmochim. Acta 68, 881-891, 2004) do exist matter. This analysis also preeised strength effect meteorites, yielding ah estimated local concentration N = 5.1020 spin/g, two orders magnitude than average meteor- ite. important note such authors syn- thetic hydrogenated amorphous carbon. seems common feature synthetic extraterrestrial (abiotic) matters, radieals are homogeneously dis- tributed