Growth and characterization of a new inorganic metal-halide crystal structure, InPb₂Cl₅

A new solid-state inorganic compound, indium dilead penta-chloride, InPb₂Cl₅, was synthesized by melting InCl and PbCl₂ in a vacuum-sealed quartz ampoule. The ampoule was heated to 793 K and then slowly cooled to room temperature to induce crystallization of InPb₂Cl₅. InPb₂Cl₅ crystallizes in the monoclinic crystal system adopting a space group of type P2₁/c, which is isostructural with other metal halides such as RbPb₂Cl₅, KPb₂Cl₅ and TlPb₂Cl₅. The bulk InPb₂Cl₅ exhibits a metallic black/grey colour, allowing it to be separated from white/yellow PbCl₂ crystals. Due to the incongruent nature of the compound, the pure bulk InPb₂Cl₅ was not obtained. The black/grey InPb₂Cl₅ crystals were characterized by powder and single-crystal X-ray diffraction. InPbCl₃ was also explored, however the growth was unsuccessful.