Syntheses and solid state structures of europium and terbium complexes of N,N'-bis(2-pyridylmethyl)urea and N,N'-bis(3-pyridylmethyl)oxalamide

摘要

Two organic ligands, N,N'-bis(2-pyridylmethyl)urea, "2u", and N,N'-bis(3-pyridylmethyl)oxalamide, "3o", were employed in the synthesis of three new extended structures. The reaction between EUC3 (.) 6H(2)O (1) and 2u afforded a molecular species, Eu(2uH(2))Cl-5, which assembled in one-dimensional chains by hydrogen bonding. When EuCl(3)(.)6H(2)O was replaced by TbCl(3)(.)6H(2)O, the reaction with 2u yielded another molecular compound, Tb(2uH(2))Cl-5, having the same structural features as 1.3o reacted with EuCl(3)(.)6H(2)O and formed compound 3, [Eu(3oH)(H2O)(2)Cl-3]Cl, in which the 3o ligand acts as a bridge between the metal centers to form an infinite one-dimensional chain structure. The chains are further linked in three dimensions by hydrogen bonds and pi-pi stacking. Luminescence data for all three compounds are presented. (C) 2003 Elsevier Ltd. All rights reserved.