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The first neutral 2D heterometallic assemblies based on orbitally degenerate heptacyanidorhenate(IV) were prepared and structurally characterized. An analysis of the magnetic data for the polycrystalline samples of Ph4P[{Mn(acacen)}2Re(CN)7]·Solv (1) and PPN[{Mn(acacen)}2Re(CN)7]·Solv (2) have shown that both materials display slow magnetic relaxation at temperatures below 10 and 21 K for 1 and 2, respectively. Despite the presence of the same molecular magnetic modules that make up the anionic layers, the studied 2D networks differ significantly in magnetic anisotropy, having a small coercive field (0.115 T) for 1 and a large one (~2.5 T) for 2 at 2 K. In addition, for both polymers a M(H) value does not saturate at the maximum available field of 7 T, and the material 2 is a metamagnet. This intriguing difference originates from the cooperative anisotropic spin interaction in ReIV−CN−MnIII pairs and the zero field splitting (ZFS) effect of MnIII ions with a noncollinear alignment of the local magnetic axes in crystals of the compounds. [ABSTRACT FROM AUTHOR]

The reaction of [ α -P₂W 15 O 56 ] 12- with Mn II and Dy III in an aqueous basic solution led to the isolation of an all inorganic heterometallic aggregate Na 10 (OH₂) 42 [{Dy(H₂O)₆}₂Mn₄P₄W 30 O 112 (H₂O)₂]·17H₂O ( Dy₂Mn₄-P₂W 15 ). Single-crystal X-ray diffraction revealed that Dy₂Mn₄-P₂W 15 crystallizes in the triclinic system with space group P 1 ¯ , and consists of a tetranuclear manganese(II)-substituted sandwich-type phosphotungstate [Mn₄(H₂O)₂(P₂W 15 O 56 )₂] 16- ( Mn₄-P₂W 15 ), Na, and Dy III cations. Compound Dy₂Mn₄-P₂W 15 exhibits a 1D ladder-like chain structure based on sandwich-type segments and dysprosium cations as linkers, which are further connected into a three-dimensional open framework by sodium cations. The title compound was structurally and compositionally characterized in solid state by single-crystal XRD, powder X-ray diffraction (PXRD), Fourier-transform infrared spectroscopy (FTIR), thermogravimetric (TGA), and elemental analyses. Further, the absorption and emission electronic spectra in aqueous solutions of Dy₂Mn₄-P₂W 15 and Mn₄-P₂W 15 were studied. Also, magnetic properties were studied and compared with the magnetic behavior of [Mn₄(H₂O)₂(P₂W 15 O 56 )₂] 16- ., Competing Interests: The authors declare no conflicts of interest.