Syntheses, structures, and luminescent and magnetic properties of novel three-dimensional lanthanide complexes with 1,3,5-benzenetriacetate

Five novel lanthanide complexes with the formulas [Nd(bta)(H2O)2(.)4.35H(2)O]n (1), [Sm(bta)(H2O)(2)(.)4.5H(2)O](n), (2), [Eu(bta)(H2O)(.)1.48H(2)O](n) (3), [Tb(bta)(H2O)(.)1.31 H2O](n) (4), and [Yb(bta)(H2O)(H2O)-H-.](n) (5) (H(3)bta = 1,3,5-benzenetriacetic acid) have been prepared by using the corresponding lanthanide salt and H3bta. The results of an X-ray crystallographic analysis revealed that all the complexes have three-dimensional channel-like structures, in which the bta(3-) ligands adopt different coordination modes: monodentate and mu(2)-eta(2):eta(1)-bridging coordination modes in 1, 2, and 5 and mu(2)-eta(1):eta(1) -bridging and mu(2)-eta(2):eta(1)-bridging coordination modes in 3 and 4, respectively. Complexes 1 and 2, as well as 3 and 4, are isostructural, respectively, in which all the Ln(III) (Ln = Nd, Sm, Eu, and Tb) atoms are nine-coordinated, while the Yb-III atoms in complex 5 are eight-coordinated. Both complexes 3 and 4 showed strong luminescence upon excitation, and their luminescence decay curves fit well with single exponential decays of which the lifetime is 0.45 ms for 3 and 1.0 ms for 4. The magnetic properties of the complexes were investigated in the temperature range of 1.8-300 K.