Holo‐ and Hemidirected Coordination Spheres in a Novel Three‐Dimensional Polymeric KIPbII Heteropolynuclear Complex: X‐Ray Crystal Structure of [KPb(AcO)2(SCN)]n

A novel three‐dimensional polymeric K^IPb^II heteropolynuclear complex, KPb(AcO)₂(SCN)]_n, with mixed acetate and thiocyanate ligands, has been synthesized and characterized. Its single‐crystal X‐ray structure (Fig. 1) shows three types of K⁺ ions with coordination numbers of seven, and three types of Pb²⁺ ions with coordination numbers of eight, eight, and nine, respectively. The Pb centers (Pb(1) and Pb(3); Fig. 1) with coordination numbers of nine and eight, respectively, possess stereochemically ‘inactive’ electron lone pairs, and the coordination sphere is holodirected. However, the arrangement of O‐, N‐, and S‐atoms for the eight‐coordinated Pb(2) suggests a gap or hole in the coordination geometry around this atom. This ‘hole’ is possibly occupied by a stereochemically ‘active’ electron lone pair of Pb(2), and its coordination sphere is, thus, hemidirected.