The synthesis and structural characterization of a family of barium thiolates and selenolates is described. The thiolates were synthesized by metallation of thiols, the selenolates by reductive insertion of the metal into the selenium ยฑ selenium bond of diorganodiselenides. Both reaction sequences were carried out by using barium metal dissolved in ammonia; this afforded barium thiolates and selenolates in good yield and purity. The structural principles displayed in the target compounds span a wide range of solid-state formu-lations, including monomeric and dimeric species, and separated ion triples, namely [Ba(thf) 4 (SMes*) 2 ] (1; Mes* 2,4,6- and [Ba([18]crown-6)(SeTrip) 2 ] (5). The full range of association modes is com-pleted by [Ba([18]crown-6)(hmpa)S-Mes*][SMes*] (6) communicated earlier by this group. In the solid state, this compound displays an intermediate ion coordination mode: one anion is bound to the metal, while the second one is unassociated. Together these compounds provide structural information about all three different association modes for alkaline earth metal derivatives. This collection of structural data allows important conclusions about the influence of solvation and ligation on structural trends.