Magnetic and Luminescent Properties of Sm, Eu, Tb, and Dy Coordination Polymers with 2‐Hydroxynicotinic Acid

By using multidentate ligand 2‐hydroxynicotinic acid (H 2 nica), six new lanthanide coordination polymers [Sm(Hnica)(H 2 O) 2 SO 4 ] n ( 1 ), {[Sm 3 (Hnica) 6 (H 2 O) 6 (OH)] · 3H 2 O · SO 4 } n ( 2 ), [Eu(Hnica)(H 2 O) 2 SO 4 ] n ( 3 ), {[Eu 3 (Hnica) 6 (H 2 O) 6 (OH)] · 6H 2 O · SO 4 } n ( 4 ), {[Tb(Hnica) 2 (H 2 O) 2 ]ClO 4 · H 2 O} n ( 5 ), and {[Dy(Hnica) 2 (H 2 O) 2 ]ClO 4 · H 2 O} n ( 6 ) were synthesized and characterized by elemental analysis, IR spectra, and X‐ray single‐crystal diffraction. Compounds 1 and 3 exhibit a 1D Ln–O–Ln chain structure. Compounds 2 and 4 show a 2D Kagomé lattice structure, whereas 5 and 6 display a 2D rhombic grid structure. The luminescent properties of 1 – 6 at room temperature were studied. Direct‐current (dc) magnetic susceptibility studies reveal antiferromagnetic interactions between Ln III ions in 1 – 6 , and alternating‐current (ac) magnetic susceptibility data of 6 suggests frequency‐dependent out‐of‐phase signals below 5 K.