(CuBr)3P4Se4: A Low Symmetric Variant of the (CuI)3P4Se4 Structure Type

Abstract

AbstractBright orange (CuBr)3P4Se4 is obtained from the reaction of CuBr, P, and Se in stoichiometric amounts (CuBr : P : Se = 3 : 4 : 4). The composition and the crystal structure of the compound were determined from single crystal X‐ray diffraction data. Lattice constants are a = 33.627(2) Å, b = 6.402(1) Å, c = 19.059(1) Å, β = 90.19(3) °, V = 4103.2(3) Å3, and Z = 12. The compound crystallizes in a structure that is related to (CuI)3P4Se4. Cages of β‐P4Se4 are stacked along the b‐axis and are separated by columns of copper(I) bromide. However, the coordination of the β‐P4Se4 cage molecules to the copper atoms in the CuBr columns in (CuBr)3P4Se4 is quite different from (CuI)3P4Se4. The monoclinic compound (space group: P21, no. 4) has an almost orthorhombic metric in combination with a threefold superstructure in [100]. Structural aspects of (CuBr)3P4Se4 are discussed with respect to the heavier homologue (CuI)3P4Se4.