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, Co(5)MS(8)L(6)(+) (L = PEt(3), M = Mn, Fe, Co, Ni) and Co(5-x)Fe(x)S(8)L(6)(+) (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 Co(5)MnS(8)L(6)(+) and Co(5)FeS(8)L(6)(+) towards the first ligand loss in comparison with their Co(6)S(8)L(6)(+) and Co(5)NiS(8)L(6)(+) counterparts and provide insights into the core-ligand interaction.