The majority of studies involving octahedral hexanuclear clusters have focused on the synthesis and structural characterization of these complexes. There are very few studies which investigate the reactivity of the ligands coordinated to hexanuclear cluster cores. Since ligand reactivity is a rich area of chemistry for single-metal centers, there is a great deal of interest in seeing how hexanuclear cluster cores affect the reactivity of coordinated ligands. This presentation will focus on reactivity studies involving the [Mo₆(μ₃-Cl)₈]⁴⁺ and the [Re₆(μ₃-Se)₈]²⁺ cores. Specifically, the reactivity of coordinated thiolate and acetonitrile ligands will be discussed.