Poly[[mu]₂-chloro-[mu]₂-1,4-oxathiane-[kappa]²S:S-copper(I)]

The title complex, [CuCl(C₄H₈OS)]_n, contains infinite spiral (CuS)_n chains linked by bridging Cl atoms into layers. The Cl atoms do not form polymeric fragments with Cu^I, but combine into isolated centrosymmetric Cu₂Cl₂ units. The compound is non-isomorphous with the Br-containing analogue, which contains Cu₈S₈ rings linked by Br atoms into chains. The O atom of the 1,4-oxathiane mol­ecule does not realize its coordination abilities in the known copper(I)-halide complexes, while in copper(II)-halide complexes, oxathiane is coordinated via the S and O atoms. This falls into a pattern of the preferred inter­actions, viz. weak acid (Cu^I atom) with weak base (S atom) and harder acid (Cu^II atom) with harder base (O atom).