Lanthanide Complexes of 2,6‐dihydroxybenzoic Acid: Synthesis, Crystal Structures and Luminescent Properties of [nbu4n]2[ln(2,6‐dhb)5(h2o)2] (ln = Sm and Tb)

Lanthanide complexes of 2,6-dihydroxybenzoic acid (2,6-Hdhb), namely [nBu(4)N](2)[Ln(2,6-dhb)(5)(H2O)(2)] [Ln = Sm (1) and Tb (2)], were synthesized and their crystal structures determined by single-crystal X-ray diffraction studies. The 2,6-dhb-ligand coordinates to the lanthanide cations through the carboxylate group in a monodentate or bidentate chelating coordination mode. The compounds were further characterised using IR, Raman, H-1 and C-13 NMR spectroscopy and elemental analysis. Photoluminescence measurements were performed on both compounds. In particular, the terbium complex 2 shows intense photoluminescence both in the solid state and in ethanolic solution. Compound 2 also exhibits triboluminescence. (C) Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2003.