Isomeric photoluminescent lead(II) coordination polymers based on designed pyridinecarboxylate ligands

The hydrothermal reaction of Pb(OAC)2·3H2O with the flexible multidentate ligand 5-(pyridin-2-ylmethoxy)-isophthalic acid (H2L1) or 5-(pyridin-4-ylmethoxy)-isophthalic acid (H2L2), respectively, afforded two new metal–organic frameworks, [Pb2L12]n (1) and [Pb2L22]n (2). The single-crystal X-ray analysis shows that 1 is a two-dimensional (2D) layered structure, whereas 2 is a three-dimensional (3D) pillar-layered network. Both of them exhibit strong yellow photoluminescence upon excitation 366 nm at room temperature.