Synthesis, structures and magnetic properties of two self-assembly uniform nets (10,3), containing three-connected nodes

Two three-dimensional (3D) coordination polymers {[NaFe(dipic)2(H2O)2]}∞ (1) and {[NaCr(dipic)2(H2O)2]}∞ (2) containing Fe5Na5 and Cr5Na5 mixed d-/s-block subunits were synthesized by the reactions of tridentate ligand H2dipic (pyridine-2,6-dicarboxylic acid) with Fe(ClO4)3 · 6H2O or Cr(ClO4)3 · 6H2O through the self-assembly process with sodium ions. The X-ray diffraction analyses reveal that both complexes have 3D (10,3) topology. Magnetic susceptibility measurements of both complexes in the temperature range of 2–300 K reveal the occurrence of weak antiferromagnetic interactions together with zero-field splitting effects.