Cyanide-Bridged Fe-Co Polynuclear Clusters Based on Four-Coordinate Cobalt(II).

Treatment of CoCl·6HO and tris(pyrazolyl-1-yl)borate tricyanoiron(III) anions at 55 °C afforded a series of new Fe-Co polynuclear clusters: {CoCl(DMF)[(Tp)Fe(CN)]} (; Tp = hydridotris(4-methylpyrazol-1-yl)borate), (HO)@{CoCl[(Tp)Fe(CN)]} (), (MePhP){CoCl[(Tp)Fe(CN)]}·15CHCN·3CHOH·2HO (), and (BnEtN){CoCl[(Tp*)Fe(CN)]}·4CHCN·2HO (; Tp*= hydridotris(3,5-dimethylpyrazol-1-yl)borate). They feature an asymmetric [FeCo(CN)] square, a pseudocubic [FeCo(CN)] cluster, a distorted-hexagonal-prism-shaped [FeCo(CN)] cage, and a bis(trigonal-bipyramidal) cluster of [FeCo(CN)] fused at one cobalt center, respectively. The Co(II) ions adopt a four-coordinate tetrahedral geometry except for half of in an octahedral geometry. It should be mentioned that and provide two novel molecular skeletons in the cyanometalate family. Interestingly, behaved as a single-molecule magnet with an effective energy barrier for spin reverse of 30.7 K at zero dc field. Our result demonstrated a possible self-assembly route toward high-nuclearity cyanide-bridged clusters by introducing four-coordinate cobalt(II) ions.