Syntheses, structures and luminescence properties of two series of 3D lanthanide coordination polymers based on benzimidazole-5,6-dicarboxylic acid and oxalate

► Two series of 3D lanthanide-organic frameworks have been synthesized solvothermally. ► The lattice and coordinated water molecules are absent under a higher temperature. ► They are constructed firstly by benzimidazole-5,6-dicarboxylic acid and oxalic acid.