Hybrid Open Networks (MIL 16):  Synthesis, Crystal Structure, and Ferrimagnetism of Co4(OH)2(H2O)2(C4H4O4)3·2H2O, a New Layered Cobalt(II) Carboxylate with 14-Membered Ring Channels

A new layered cobalt succinate, Co4(OH)2(H2O)2(C4H4O4)3·2H2O, was prepared under hydrothermal conditions at 180 °C from a 1:1.5:4:120 mixture of Co(II) chloride hexahydrate, succinic acid, potassium hydroxide, and water. The structure was solved by single-crystal X-ray diffraction: P1̄, a = 10.181(2), b = 10.668(2), c = 12.857(2) Å, α = 112.97(3)°, β = 91.24(3)°, γ = 117.96(3)°, V = 1099.1(4) Å3, Z = 2, 5511 F2 values with I = 2σ(I), R1 = 0.045 and wR2 = 0.114. The title compound presents a structure constituted by the stacking along 100 of metal oxide layers in which 14-membered ring windows appear. Succinate anions linked the cobalt atoms within each layer. From magnetization measurements, this compound is ferrimagnetic below 10 K.