1D and 2D Zn-Ln coordination polymers based on compartment compounds: [ZnLn(L)(NO3)(2)(4-Ppa)(EtOH)] and [ZnLn(L)(NO3)(2)(4-pca) (H2O)] (Ln = Eu, Tb; H-2 L=1,3-bis((3-methoxysalicylidene)amino) propane; 4-Hppa=4-pyridinepropionic acid; 4-Hpca=4-pyridinecarboxylic acid)

Abstract

This paper describes the preparation of four 3d-4f (3d = Zn; 4f = Eu, Tb) coordination polymers and their emission quenching of the lanthanide ions. Two dinuclear Zn-Ln compartment compounds, [ZnLn(L) (NO3)(CH3CN)(H2O)(4)](NO3)(2)(H2O) (Ln = Eu, Tb), were prepared at room temperature by stirring an acetonitrile solution containing [Zn(L)] (H-2 L = 1,3-bis((3-methoxysalicylidene)amino)propane) and Ln (NO3)(3 center dot)n(H2O). When these compounds were treated with 4-pyridinepropionic acid (4-Hppa) under microwave-heating conditions, one-dimensional Zn-Ln coordination polymers were formed: [ZnLn(L) (NO3)(2)(4-ppa)(EtOH)] (Ln = Eu (1), Tb (2)). By contrast, these compounds reacted with pyridine-4-car-boxylic acid (4-Hpca) to give two-dimensional Zn-Ln coordination polymers: [ZnLn(L)(NO3)(2)(4-pca) (H2O)] (Ln = Eu (3), Tb (4)). All the compounds (1-4) exhibited the emission quenching of the Ln(3+) ion, probably due to the Ln(3+) -> Zn2+ energy transfer. (C) 2016 Elsevier Ltd. All rights reserved.