In the title polymeric complex, [Fe{OS(CH3)2}2{Ag(CN)2}2], the FeII cation is located at an inversion centre and is coordinated by four cyanide (CN-) anions and two dimethyl sulfoxide mol-ecules in a slightly compressed N4O2 octa-hedral geometry, the AgI cation is C-coordinated by two CN- anions in a nearly linear geometry. The CN- anions bridge the FeII and AgI cations to form a two-dimensional polymeric structure extending parallel to (102). In the crystal, the nearest Ag⋯Ag distance between polymeric sheets is 3.8122 (12) Å. The crystal studied was a twin with a contribution of 0.2108 (12) for the minor component.
Keywords: FeII complex; Hofmann clathrate analogue; crystal structure; dicyanidoargentate; metal–organic framework.