Poly[bis(μ‐5‐iodoisophthalato)(methanol)dilead(II)] exhibiting a novel centrosymmetric rhombus‐shaped I4 unit

The asymmetric unit of the title compound, Pb₂(C₈H₃IO₄)₂(CH₄O)]_n, contains two Pb^II atoms, two 5‐iodoisophthalate (5‐IIP^2?) ligands and one coordinated methanol molecule. One Pb atom is eight‐coordinated, surrounded by seven carboxylate O atoms from five 5‐IIP^2? ligands and one O atom from the terminal methanol ligand. The other Pb atom is seven‐coordinated in a hemidirected geometry, surrounded by seven carboxylate O atoms from five 5‐IIP^2? ligands. Both Pb atoms are connected by carboxylate groups to form a one‐dimensional infinite rod along the a axis; neighbouring rods are further linked by the aromatic rings of 5‐IIP^2? to generate the final three‐dimensional structure with channels in the a direction. An O—H...O hydrogen bond between the methanol ligand and one of the carboxylate groups of a 5‐IIP^2? ligand stablizes the three‐dimensional framework. Interestingly, a centrosymmetric rhombus‐shaped I₄ unit is formed by four 5‐IIP^2? ligands, with I...I distances of 3.8841 (8) and 3.9204 (8) Å.