centrosymmetric sandwichcomplex cation [Ag(mn12S 4 ) 2 ] + where each mn12S 4 ligand is coordinated to the Ag centre in an endo manner through all four S atoms. The 2:1 complex [Ag(mn12S 4 ) 2 ] + is the firstsandwichcomplex with a tetrathiacrown ether and the firstcomplex with an octa(thioether) coordinationsphere. The crystal structure of compound 4a also reveals a 2:1 complex. This complex, [Ag(mn13S