3D Ln–Ag (Ln = Nd; Eu) coordination polymers based on N- and O-donor ligands: Synthesis, crystal structures and luminescence

The self-assembly of isonicotinic acid with metal salts under hydrothermal conditions gave two isostructural 3D 4d–4f coordination polymers, Ln2Ag4(OX)(IN)6(H2O)1.5 · 2(ClO4) [Ln = Nd (1); Eu (2), OX = oxalic acid, IN = isonicotinic acid]. Compounds 1 and 2 are 3D coordination frameworks via 2D layers built by carboxylate groups of isonicotinic acid and oxalate ligands coordinating to metal centers and completing the linear linker by silver ions. Furthermore, the luminescent properties of complex 2 have also been investigated.