Lanthanide coordination polymers with N-methyliminodipropionic acid: Synthesis, crystal structures and luminescence

The synthesis, crystal structures and luminescence of a novel family of lanthanide polymer complexes with general formula [Ln(2)(Hmidp)(3)(H2O)(3)](ClO4)(3)center dot 6H(2)O (Ln = Nd, Sm, Eu, Gd, Dy, Ho, Tm; H(2)midp = N-methyliminodipropionic acid) are reported. The compounds were obtained by direct reaction of H(2)midp and lanthanide(III) perchlorate in aqueous solution. The choice of the conditions of synthesis were selected from speciation studies. The structure of the polymer complexes contains bimetallic cationic units [Ln(2)(Hmidp)(3)(H2O)(3)](3+) in which one of the Ln ions is eight- coordinated and the other nine- coordinated, linked by carboxylate bridges. This is expanded to a 2D network through carboxylate linkers. The solid state luminescence of the Eu complex was observed and an average lifetime value of 0.5 ms was verified for the red emitting D-5(0) excited state. (C) 2017 Elsevier B.V. All rights reserved.