Crystal Structure of PbI2(ethylenediamine)2, catena-μ-Ethylenediamine-ethylenediaminediiodolead(II) at -150°C

The title complex is triclinic, P1, a = 7.585(3), b = 7.688(4), c = 12.737(6)A, α = 83.22(2), β = 73.731(19), γ = 63.38(2)°, V = 637.4(5)°3, and Z = 2 at -150°C; R is 0.0242. The structure shows a one-dimensional polymer extending along [111] with two crystallographically independent inversion centers lying at the middle of the C-C bond of each bridging ethylenediamine (en). The Pb atom is coordinated by two I atoms and four N atoms: the two I atoms occupy a cis-position, the two N atoms of a chelating en lie opposed to them, and the four atoms lie in a plane containing the Pb atom; the other two N atoms of the bridging en ligands lie at both axial positions. Since the I-Pb-I angle is 144.57(1)° wide, the Pb environment geometry might be described as being a distorted pentagonal bipyramid, providing a stereochemically active lone pair of electrons of the Pb atom may occupy one coordination site.