A hybrid cobalt disulfonate with a novel inorganic layer architecture exhibiting a field-induced magnetic transition

We report the synthesis, crystal structure, and magnetic properties of Co₃(OH)₄(ethanedisulfonate), a layered cobalt hydroxide pillared by ethanedisulfonate ligands (P2₁/c, a = 8.9462(6) , b = 5.2818(4) , c = 10.1259(7) , β = 93.297(2)°, V = 477.68(6) ³, Z = 2). The structure displays two-dimensional infinite Co-O-Co connectivity, with the octahedra forming what we believe is a novel M ₃X₈ inorganic layer topology; brucite-like ribbons of edge-sharing octahedra share corners with other ribbons along a second direction to form perforated layers of octahedra. Magnetic measurements reveal a sharp peak in susceptibility at 38 K, with a Curie-Weiss constant of -243 K and an effective magnetic moment (_eff) of 4.35 _B per Co. A field-induced transition from a triangular antiferromagnetic to a collinear ferrimagnetic state occurs in high fields. Heat capacity measurements indicate a relatively small magnetic entropy change, suggesting that the magnetic ordering is only two-dimensional. Thermogravimetric analysis and differential thermal analysis of the material show stability to 350 °C.