Single-molecule magnets constructed from cyanometalates:: {[Tp*FeIII(CN)3MII(DMF)4]2[OTf]2}•2DMF (MII = Co, Ni)

Treatment of several divalent transition-metal trifluoromethane-sultonates [M-II(OTf)(2); M-II = Mn, Co, Ni] with [NEt4][Tp*Fe-III(CN)(3)] [Tp* = hydridotris(3,5-dimethylpyrazol-1-yl)borate] in DMF affords three isostructural rectangular clusters of {Tp*Fe-III(CN)(3)M-II(DMF)(4)](2)-[OTf](2)1}-2DMF (M-II = Mn, Co, Ni,] stoichiometry. Magnetic studies of 3-5 indicate that the Tp*Fe(CN)(3)(-) centers are highly anisotropic and exhibit antiferromagnetic (3 and 4) and ferromagnetic (5) exchange to afford S = 4, 2, and 3 spin ground states, respectively. ac susceptibility measurements suggest that 4 and 5 exhibit incipient single-molecule magnetic behavior below 2 K.