Magnetic Correlation Engineering in Spin-Sandwiched Layered Magnetic Frameworks

The insertion of “sandwiched spins” between magnetic layers could efficiently affect the interlayer magnetic correlations, but doing so increases the complexity in the interlayer spin alignment because of competition between the inserted spin-layer interaction J_NNI and the interlayer through-space interaction J_NNNI if the magnitude of J_NNI is of the same order as J_NNNI with reciprocal signs of the respective interactions. Herein, systematic tuning of the magnetic phase variations by J_NNI and J_NNNI in two kinds of metal-variable isostructural series of supramolecular pillared layer magnets [MCp*₂][{Ru₂^II,II(2,3,5,6-F₄CO₂)₄}₂(TCNQ)] ⋅ 2 DCE (M=Co, Fe, Cr; 2,3,5,6-F₄PhCO₂⁻=2,3,5,6-tetrafluorobenzoate; TCNQ=7,7,8,8-tetracyano-p-quinodimethane; DCE=1,2-dichloroethane) and their DCE-free series, in which [MCp*₂]⁺ (Cp*=η⁵-C₅Me₅) species with S=0, 1/2, and 3/2 for M=Co, Fe, Cr, respectively, are sandwiched between ferrimagnetic layers of [{Ru₂}₂(TCNQ)]⁻, is demonstrated. The results showed that the flexible magnetic natures of these magnets are changeable in dependence on J_NNI and J_NNNI, as well as on interlayer inserted spins M.