Negative‐ion/positive‐ion coincidence spectroscopy as a tool to identify anionic fragments: The case of core‐excited CHF3.

Autor: Kivimäki, Antti, Stråhlman, Christian, Sankari, Rami, Richter, Robert
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Zdroj: Journal of Mass Spectrometry; May2020, Vol. 55 Issue 5, p1-9, 9p
Abstrakt: We have studied the dissociation of the trifluoromethane molecule, CHF3, into negative ionic fragments at the C 1s and F 1s edges. The measurements were performed by detecting coincidences between negative and positive ions. We observed five different negative ions: F−, H−, C−, CF−, and F2−. Their production was confirmed by the analysis of triple coincidence events (negative‐ion/positive‐ion/positive‐ion or NIPIPI coincidences) that were recorded with cleaner signals than those of the negative‐ion/positive‐ion coincidences. The intensities of the most intense NIPIPI coincidence channels were recorded as a function of photon energy across the C 1s and F 1s excitations and ionization thresholds. We also observed dissociation channels involving the formation of one negative ion and three positive ions. Our results demonstrate that negative‐ion/positive‐ion coincidence spectroscopy is a very sensitive method to observe anions, which at inner‐shell edges are up to three orders of magnitude less probable dissociation products than cations. [ABSTRACT FROM AUTHOR]
Databáze: Complementary Index
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