STRUCTURAL AND SPECTROSCOPIC STUDIES OF THE 2D COORDINATION POLYMERS (infinity)[Tb(DPA)(HDPA)] AND (infinity)[Gd(DPA)(HDPA)]

This paper presents the synthesis of the coordination polymers (infinity)[Ln(DPA)(HDPA)] (DPA=2,6-pyridinedicarboxylate; Ln=Tb and Gd), their structural and spectroscopic properties. The structural study reveals that the (infinity)[Ln(DPA) (HDPA)] has a single Ln(+3) ion coordinated with two H(2)DPA ligands in tridentade coordination mode, while two others H(2)DPA establish a syn-bridge with a symmetry-related Ln(3+), forming a two-dimensional structure. The spectroscopic studies show that (infinity)[Tb(DPA)(HDPA)] compound has high quantum yield (q(x)approximate to 50.0%), due to the large contribution of radiative decay rate. Moreover triplet level is localized sufficiently over the emitter level D-5(4) of the Tb3+ ion, avoiding a retrotransference process between these states.