Crystal and molecular structures of two modifications of a chelate compound of Pb[(iso-C4H9)2PS2

Abstract

A chelate compound Pb[(iso-C4H9)2PS2]2 is synthesized. Using X-ray diffraction data, the crystal structures of two modifications of this compound are determined (X8 APEX diffractometer, MoK α radiation, 14169 F hkl , R = 0.0480 for the low temperature α-form and 6261 F hkl , R = 0.0387 for the β-form studied at ambient temperature). The crystals are triclinic: a = 11.047(2) A, b = 14.486(3) A, c = 32.048(6) A; α = 91.30(3)°, β = 99.73(3)°, γ = 101.61(3)°, V = 4942.9(17) A3, Z = 8, ρcalc = 1.682 g/cm3 (α-modification) and a = 11.2124(5) A, b = 14.6989(7) A, c = 17.1644(6) A; α = 109.393(1)°, β = 94.989(2)°, γ = 101.649(1)°, V = 2576.83(19) A3, Z = 4, ρcalc = 1.613 g/cm3 (β-modification), space group \(P\bar 1\) for both polymorphs. The structures are molecular, coordination cores of PbS4 are tetragonal pyramids with Pb atoms in the vertices and S atoms in the base. In both structures intermolecular Pb...S contacts yield supramolecular ensembles comprising by four molecules, where PbS4+2 cores form planar aggregates of edge-sharing octahedra. The ensembles are joined by weak intermolecular S...S interactions resulting in the development of polymeric chains along the a axis.