A heteropolymetallic coordination polymer containing alkaline-earth (Ae) cation, lanthanide (Ln) cation and alkali (A) cation

A heteropolymetallic coordination polymer, [Ba2Tb4Na4(pdc)10(H2O)24]·(H2O)11, H2pdc = pyridine-2,6-dicarboxylic acid, has been successfully designed, synthesized under hydrothermal condition, and characterized by elemental analysis, thermal analysis, IR spectrum, luminescence, as well as X-ray crystallography. Three different kinds of metal cations (Ae, Ln and A) could be connected simultaneously by a pdc2− ligand with coordination mode i. A fundamental block consisting of 14-membered mixed-metal Ba(II)–Tb(III)–Na(I) rings was achieved, which shared common edges and constructed to form 2D infinite networks. The adjacent 2D networks were assembled into a 3D polymeric framework via O–H⋯O hydrogen bonds. Sodium hydroxide was introduced not only to deprotonate the carboxylic groups of H2pdc, but also take part in the coordination under higher temperature and pressure. The convenient synthesis developed in this paper seemed to have a wide applicability in designing new heteropolymetallic systems.