4-Methoxy-3-nitrobenzoates of light lanthanides with a metal to ligand ratio of 1:3 have been obtained as hydrated salts. They have colours typical of Ln3+ ions (Pr-green, Nd-pink, Sm-cream, and La, Ce, Eu and Gd-white). The carboxylate group appears to be a bidentate chelating ligand. 4-Methoxy-3-nitrobenzoates of light lanthanides are crystalline compounds. During heating in air, they decompose explosively. Therefore, their thermal stability was studied in the temperature range 273–523 K. The complexes dehydrate in one or three steps. The solubilities of complexes were measured in water at 293 K. They are in the order of 10–4 mol dm–3
