Gas-phase fragmentation of single heteroatom-incorporated Co5MS8(PEt3)6+ (M = Mn, Fe, Co, Ni) nanoclusters

Abstract

Functionalization of metal-chalcogenide clusters by either replacing core atoms or by tuning the ligand is a powerful technique to tailor their properties. Central to this approach is understanding the competition between the strength of the metal-ligand and metal-metal interactions. Here, using collision-induced dissociation of atomically precise metal sulfide nanoclusters, Co5MS8L6+ (L = PEt3, M = Mn, Fe, Co, Ni) and Co5-xFexS8L6+ (x = 1–3), we study the effect of a heteroatom incorporation on the core-ligand interactions and relative stability towards fragmentation. Sequential ligand loss is the dominant dissociation pathway that competes with ligand sulfide (LS) loss. Because the ligands are attached to metal atoms, LS loss is an unusual dissociation pathway, indicating significant rearrangement of the core prior to fragmentation. Both experiments and theoretical calculations indicate the reduced stability of Co5MnS8L6+ and Co5FeS8L6+ towards the first ligand loss in comparison with their Co6S8L6+ and Co5NiS8L6+ counterparts and provide insights into the core-ligand interaction.

Controlled Formation of Fused Metal Chalcogenide Nanoclusters Using Soft Landing of Gaseous Fragment Ions

“…In our previous study, we used collision-energy-resolved CID experiments of Co 5 MS 8 L 6 + (M = Mn, Fe, Co, or Ni) clusters to examine their relative stability toward ligand loss. We found that the cluster stability increases in the order Co 5 FeS 8 (L 1 ) 6 + < Co 5 MnS 8 (L 1 ) 6 + < Co 6 S 8 (L 1 ) 6 + ≈ Co 5 NiS 8 (L 1 ) 6 + , with Co 5 FeS 8 (L 1 ) 6 + being the least stable cluster . Based on the observed surface reactivity of the corresponding fragment ions generated by the removal of one ligand from each cluster, we conclude that less stable gas phase precursor ions such as Co 5 FeS 8 (L 1 ) 6 + generate more stable fragment ions that do not react efficiently on surfaces.…”

“…We found that the cluster stability increases in the order Co 5 FeS 8 (L 1 ) 6 + < Co 5 MnS 8 (L 1 ) 6 + < Co 6 S 8 (L 1 ) 6 + ≈ Co 5 NiS 8 (L 1 ) 6 + , with Co 5 FeS 8 (L 1 ) 6 + being the least stable cluster. 44 Based on the observed surface reactivity of the corresponding fragment ions generated by the removal of one ligand from each cluster, we conclude that less stable gas phase precursor ions such as Co 5 FeS 8 (L 1 ) 6 + generate more stable fragment ions that do not react efficiently on surfaces. Meanwhile, more stable precursor ions such as Co 6 S 8 (L 1 ) 6 + with Co 5 NiS 8 (L 1 ) 6 + generate more reactive fragments.…”

“…In our studies, we typically perform collision energy-resolved experiments to optimize the conditions for a particular fragmentation pathway in the gas phase. 44 By plotting the relative abundance of each fragment versus collision energy, we obtain insights into both the fragmentation pathways and optimal collision energy for each ligand removal. CID enables precise control of the building block formation in the gas phase for subsequent mass selection and deposition of well-defined ions onto surfaces.…”

“…In CID, the extent of fragmentation is controlled by varying the accelerating electric fields, which define the kinetic energy (KE) of the ion in the collision cell. In our studies, we typically perform collision energy-resolved experiments to optimize the conditions for a particular fragmentation pathway in the gas phase . By plotting the relative abundance of each fragment versus collision energy, we obtain insights into both the fragmentation pathways and optimal collision energy for each ligand removal.…”

Effect of Ligands on the Reactivity of the Undercoordinated Fragment Ions of Co6S8(PEt3–xPhx)6+ (x = 0–3) Clusters on Surfaces

“…Tandem mass spectrometry is ideally suited for preparing reactive fragments of metal chalcogenide clusters using controlled ligand removal in the gas phase . Soft landing of mass-selected fragment ions onto surfaces provides insights into their reactivity. − We have previously used this approach to examine the reactivity of the undercoordinated Co 5 MS 8 (PEt 3 ) 5 + (M = Co, Mn, Fe, and Ni) fragment ions on surfaces.…”