Field-induced slow magnetic relaxation of octahedrally coordinated mononuclear Fe(III)-, Co(II)-, and Mn(III)-containing polyoxometalates.

Herein, we report for the first time polyoxometalate (POM)-based single-molecule magnets with mononuclear transition metal cores. The mononuclear Fe(III)-, Co(II)-, and Mn(III)-containing POMs have successfully been synthesized from a trivacant lacunary Keggin-type silicotungstate precursor TBA4H6[A-α-SiW9O34]·2H2O (TBA = tetra-n-butylammonium), and the highly distorted octahedral geometries of the incorporated metal cations resulted in the magnetic anisotropies and the single-molecule magnet behavior with mononuclear paramagnetic metal ions under the applied dc field.