Redox Properties of the Diatomic Bare Iron Chalcogenides FeO and FeS in the Gas Phase

Abstract

AbstractThe electron‐transfer behavior of the binary iron chalcogenides FeO and FeS has been examined by means of mass spectrometry and ab initio calculations using the averaged coupled‐pair functional (ACPF) method. The experimental and theoretical results are in good agreement with each other and also with previous studies. The ionization energies (IE) of the diatomic species are found to be IE(FeO) = 8.8±0.2 eV, IE(FeO+) = 17.9±0.4 eV, IE(FeS) = 8.3±0.3 eV, and IE(FeS+) = 16.3±0.5 eV. Two new diatomic dications, FeS2+ and FeO2+, are shown to exist as metastable minima on the corresponding potential‐energy surfaces. The data enable an evaluation of the intrinsic gas‐phase redox properties of FeS and FeO, and the comparison demonstrates that iron sulfide is more prone to undergo facile reduction and oxidation than iron oxide.