Enforcing Ising-like magnetic anisotropy via trigonal distortion in the design of a W(v)–Co(ii) cyanide single-chain magnet† †This project was granted financial support from the Department of Energy (DE-FG02-02ER45999). Funds for the SQUID magnetometer were obtained from the National Science Foundation. ‡ ‡Electronic supplementary information (ESI) available. CCDC 1508991. For ESI and crystallographic data in CIF or other electronic format see DOI: 10.1039/c7sc02925j

A new octacyanotungstate(v) singe chain magnet with an effective energy barrier of 39.7(3) cm–1 is achieved by enforcing Ising-like magnetic anisotropy via introduction of trigonal distortion with a fac-tridentate capping ligand.
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.