Synthesis, crystal structure and Near-infrared luminescence of rare earth metal (YIII, ErIII, HoIII) complexes containing semi-rigid tricarboxylic acid ligand

Abstract Three new isostructural rare earth metal coordination polymers, [Re (L)(H2O)2]•n H2O (Re=Y, n=1 for 1; Ho, n=2 for 2; and Er, n=0 for 3), have been successfully synthesized via solvothermal reactions with three rare earth metal nitrates and a semirigid multi-carboxylate ligand H3L [H3L=4-(2-carboxyphenoxy)isophthalic acid]. Single crystal X-ray analysis reveals that complexes 1-3 are isostructural and show 2D layer frameworks connected by O atoms of the carboxyl group from H3L ligand. The near-infrared luminescence properties of complexes 2 and 3 were initially explored, which provided a possibility for further development of near-infrared photoluminescence materials and their exciting use in biomedical field.