A New Series Lanthanide-2,6-Pyridinedicarboxylic Acid Complexes Containing Low Dimensionality: Synthesis, Structure and Photoluminescent Properties

Abstract

Based on the 2,6-pyridinedicarboxylate acid ligand, ten lanthanide complexes with formula, (Hdipa)3[Ln(L)3] (Ln = Eu [1], Gd [2], Nd [3], Tb [4], Ce [5], Sm [6], Pr [7], Dy [8] and Er [9]) and [Nd(L)(HL)(H2O)2]·4H2O (10), (where H2L = 2,6-pyridinedicarboxylic acid and dipa = N-(1-methylethyl)-2-propanamine) have been prepared by different synthetic methods. Structural analyses reveal that complexes 1–3 are isomorphous, zero-dimensional structures, which are further connected to 3D H-bonding networks via extensive intermolecular hydrogen bonds. In the structures of these complexes, the dipa plays a key role in balancing electric charge. For complex 10, the 1D Ln–O–C–O–Ln polymeric chains are linked into a stable 3D H-bonding framework through numerous intermolecular and intramolecular hydrogen bonds. The luminescent properties of complexes 1, 4, 6 and 8 were investigated in detail. Based on the 2,6-pyridinedicarboxylate acid ligand, ten lanthanide complexes with formula, (Hdipa)3[Ln(L)3] (Ln = Eu [1], Gd [2], Nd [3], Tb [4], Ce [5], Sm [6], Pr [7], Dy [8] and Er [9]) and [Nd(L)(HL)(H2O)2]·4H2O (10), (where H2L = 2,6-pyridinedicarboxylic acid and dipa = N-(1-methylethyl)-2-propanamine) have been prepared by different synthetic methods. Complexes 1–9 are zero structures and 10 features a 1D Ln–O–C–O–Ln polymeric chain structure. The luminescent properties of complexes 1, 4, 6 and 8 were investigated in detail.