Tuning the oxidative power of free iron–sulfur clusters

Abstract

The gas-phase reactions between a series of di-iron sulfur clusters FeS (x = 1-3) and the small alkenes CH, CH, and CH have been investigated by means of Fourier-transform ion-cyclotron resonance mass spectrometry. For all studied alkenes, the reaction efficiency is found to increase in the order FeS < FeS < FeS. In particular, FeS and FeS only form simple association products, whereas the sulfur-rich FeS is able to dehydrogenate propene and 2-butene via desulfurization of the cluster and formation of HS. This indicates an increased propensity to induce oxidation reactions, i.e. oxidative power, of FeS that is attributed to an increased formal oxidation state of the iron atoms. Furthermore, the ability of FeS to activate and dissociate the C-H bonds of the alkenes is observed to increase with increasing size of the alkene and thus correlates with the alkene ionization energy.

Rearrangement and decomposition pathways of bare and hydrogenated molybdenum oxysulfides in the gas phase

“…[15][16][17][18][19] Reactions of small cationic iron sulfide clusters with small alkanes elucidated the oxidative power of these compounds. 20 Also molybdenum chalcogenide cations were investigated with gas-phase techniques. 21 Jarrold, Raghavachari and co-workers have focused on molybdenum oxide and sulphide cluster reactivity, [22][23][24][25][26] with studies involving H 2 and H 2 O bearing relevance for HER catalysis.…”

Decomposition of Halogenated Molybdenum Sulfide Dianions [Mo3S7X6]2–(X = Cl, Br, I)

“…Gas-phase studies offer the advantage of dealing with well-defined and controllable systems. Such investigations give conceptual insight into the structure and behavior of individual molecules or small clusters as a model system for heterogeneous catalysis. − Lang, Zhou, and Schwarz managed to obtain Fe 2 S x + ( x = 1–3) clusters and reacted them with small alkanes, which provided insight into the oxidative power of these species. Earlier, molybdenum chalcogenide cations were investigated in the Schwarz group .…”

Formaldehyde Generation in Photooxidation of Isoprene on Iron Oxide Nanoclusters

“…Studies have shown that photoreactions of iron oxides have potential to impact the transformation of VOCs in the atmosphere. , Therefore, the chemical process of isoprene on iron oxide particles will be quite interesting, and it is very beneficial for atmospheric chemistry models to obtain the mechanistic insights. The surfaces of particles are complex, while gas-phase atomic clusters are considered as ideal models of active sites on related solid surfaces. − Nanosized atomic clusters are of great importance to bridge atoms and their bulk counterpart. − …”