Design of One-Dimensional Coordination Networks from a Macrocyclic {3d-4f} Single-Molecule Magnet Precursor Linked by [W(CN)8]3- Anions

The outcome of 1:1 reactions of the tetranuclear 3d-4f Single Molecule Magnet (SMM) [Cu3Tb(L-Pr)(NO3)(2)(H2O)]NO3 (1) with (TBA)(3)[W(CN)(8)] (TBA = tri-n-butyl ammonium cation, [(n-Bu)(3)N-H](+)) in dimethylformamide (DMF) is dependent on the crystallization method employed: liquid liquid diffusion of the reagents together gives {[Cu3Tb(L-Pr)W(CN)(8)(DMF)(4)]center dot(DMF)}(n) (2) whereas diethyl ether vapor diffusion into the reaction solution gives {[Cu3Tb(L-Pr)W(CN)(8)(DMF)(3)(H2O)(3)]center dot(DMF)(1.5)center dot(H2O)(0.5)}(n) (3). Both compounds are obtained as black single crystals and feature one-dimensional (1D) coordination networks (chains) of [1](3+) macrocycles linked by [W(CN)(8)](3-) anions. The two assemblies differ from a structural point of view. Complex 2 has a stepped arrangement with the linkers bound to the opposite faces of the macrocycle, whereas 3 has a square-wave arrangement due to the linkers binding to the same face of the macrocycle. Both compounds display an antiferromagnetic ground state below 3.5 and 2.4 K with a metamagnetic and antiferromagnetic (T, H) phase diagram for 2 and 3, respectively. Remarkably the slow dynamics of the magnetization of the [1](3+) macrocycle units is preserved in 3 while this property is quenched in 2 because of stronger intra- and interchain magnetic interactions inducing a higher critical temperature.