Nanoporous R-SnS-n materials, e.g. (Et4N)2Sn3S7, have recently been synthesized and characterized. The crystal structures of two molecular tin(IV) sulfide species that are thought to be important in the formation of these materials are reported. Both contain the dimer (Sn2S6)4-, which can be combined (see Figure) to form the Sn3S4 broken-cube clusters that constitute the open framework of R-SnS-1.