Three-dimensional molecular-based magnet of octacyanometalate-based tungstate(V)-cobalt(II) bimetallic assembly with TC = 26 K

A three-dimensional (3D) octacyanotungstate(V)-based molecular based magnet containing Co(II) ions, {[CoII4(H2O)6(C2O4)][WV(CN)8]2·6H2O}n (1), has been synthesized in acidic solution and structurally characterized. X-ray determination indicates that in 1 each [W(CN)8]3 − structural unit is linked by seven neighboring Co(II) ions forming 2D Co–W–CN inorganic connectivity layers. Further short conjugated oxalate bridges join these neighboring 2D layers ultimately forming the 3D framework. Magnetic investigation of complex 1 reveals that long-range ferromagnetic ordering occurs below the Curie temperature of 26 K. The beautiful butterfly-shaped magnetic hysteresis loop at 10 K between − 70 KOe and 70 KOe exhibits a rather high coercive field (HC = 3010 Oe). The remnant magnetization Mr is equal to 3055 cm3 mol− 1. To our best knowledge, complex 1 is the first example of 3D cyano-based magnets bridged by C2O42 − anions.