Pyrazolylborates And Their Importance In Tuning Single-Molecule Magnet Properties Of {(Fe2niii)-Ni-Iii} Complexes

A new tricyanoferrate(III) building block and a trinudear single-molecule magnet derivative are described. The treatment of a 2:1 ratio of [NEt4] [(Tp*(Bn))Fe-III-(CN)(3)]center dot H2O center dot MeOH [1; Tp*(Bn) = tris(3,5-dimethyl-4-benzyl)pyrazolylborate] with nickel(II) trifluoromethanesulfonate gives {[(Tp*(Bn))Fe-III(CN)(3)](2)[Ni-II(DMF)(4)]} center dot 2DMF (2; DMF = N,N-dimethylformamide). The symmetry-equivalent Fe-LS(III) ions lead to a favorable alignment of anisotropy tensors (i.e., Fe center dot center dot center dot B axes) in 2, and an energy barrier of Delta(eff)/k(B) = 16.7 K is found for the S-T = 2 complex.