ZnPCl ₇ : a compositionally and structurally unprecedented metal–phosphorus halide

The synthesis and crystal structure of an unprecedented compound, zinc phospho-rus hepta-chloride or <i>catena</i>-poly[phospho-rus tetra-chloride [[di-chlor-ido-zinc]-μ-chlorido]], ZnPCl₇ or {[PCl₄][ZnCl₃]} _<i>n</i> , are reported. The reaction of ZnCl₂ with PCl₅ in a 1:1 molar ratio at 623 K produced single crystals of ZnPCl₇, which crystallizes in the ortho-rhom-bic space group <i>Ama2</i>. The Zn and P atoms lie on crystallographic mirror planes, as do four of the Cl atoms. One Cl atom lies on a twofold axis and one occupies a general position. Its extended structure features isolated [PCl₄]⁺ tetra-hedra and one-dimensional chains of corner-sharing ZnCl₂Cl_2/2 tetra-hedra. Bond-valence sum calculations support the assignment of formal oxidation states. This discovery extends the compositional and structural landscape of mixed-metal halides.