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, Co-4(OH)(2)(H2O)2(C4H4O4)(3). 2H(2)O, was prepared under hydrothermal conditions at 180 degrees 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: P (1) over bar, a = 10.181(2), b = 10.668(2), c = 12.857(2) Angstrom, alpha = 112.97(3)degrees beta = 91.24(3)degrees, gamma = 117.96(3)degrees V = 1099.1(4) Angstrom(3), Z = 2, 5511 F-2 values with I = 2 sigma(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.