Novel coordination mode of chloride ion in holo- and hemidirected one-dimensional PbII coordination polymer

A new lead(II) chloride coordination polymer with the ligand 4′-(4-pyridyl)-2,2′:6′,2″-terpyridine (pyterpy), [Pb3(pyterpy)2(μ2-Cl)3(μ3- Cl)3]n · nMeOH, has been synthesized and structurally analyzed by X-ray single-crystal diffraction. Its single-crystal X-ray structure shows the complex is one-dimensional polymer as a result of chloride unusual bi- and tridonor bridging and also shows three types of Pb2+-ions with coordination numbers of six (Pb1 and Pb2) and eight Pb3. The Pb1 and Pb3 centers possess the coordination sphere of holodirected. However, the arrangement of Cl- and N-atoms for Pb2 suggests a gap or hole in the coordination geometry around this atom and its coordination sphere is, thus, hemidirected.