Homodinuclear lanthanide 9-anthracenecarboxylate complexes: Field induced SMM and NIR-luminescence

Abstract

Six homodinuclear lanthanide complexes with formula [Ln2(μ2-9-AC)4(9-AC)2(phen)2] (Ln(III) = Nd (1), Eu (2), Gd (3), Tb (4), Er (5) and Yb (6) are reported and complexes 1–3 and 6 are structurally characterized. 9-HAC = 9-anthracenecarboxylic acid, phen = 1,10-phenanthroline. The luminescence properties of compounds 1–6 have been studied at different temperatures in the solid state and show the sensitization of the 4f–4f emission bands in the NIR range for compounds 1, 5 and 6. The molar magnetic susceptibility measurements of 1–6 in the 2–300 K temperature range indicate weak antiferromagnetic exchange for the isotropic Gd(III) compound 3. Furthermore, slow relaxation of the magnetization is found in complexes 5 and 6 with effective energy barriers of 9.5 cm−1 (0.1 T) and 22.7 cm−1 (0.15 T), respectively.