Enforcing Ising-like magnetic anisotropy via trigonal distortion in the design of a W(v)-Co(ii) cyanide single-chain magnet.

A new octacyanotungstate(v) based single chain magnet {[(Tpm)Co(DMF)W(CN)8]2[Co(DMF)4]·2DMF} n (1, Tpm = 1,1,1-trispyrazoylmethane), with an effective barrier of 39.7(3) cm-1 is reported. The Ising-like magnetic anisotropy of the chain originates from the nearly parallel local orientations of the Co(ii) ions with the source of the uniaxial magnetic anisotropy being a trigonal distortion of the octahedral environment with the fac-tridentate capping Tpm ligand.