Slow Magnetic Relaxation in Neutral 0D and 1D Assemblies of a Mn(III) Schiff Base Complex and Heptacyanorhenate(IV).

The first neutral 0D and 1D heterometallic assemblies based on orbitally degenerate heptacyanidorhenate(IV) were prepared and structurally characterized. An analysis of the magnetic data of polycrystalline samples showed that both compounds display slow magnetization relaxation at temperatures below 5 K. The very low temperature measurements of the magnetization on the single crystals demonstrate that for the 1D compound {[Mn(SB²⁺)Re(CN)₇]·7H₂O}_n (1) and the 0D complex [Mn(SB²⁺)(H₂O)Re(CN)₇]·2H₂O (2), the hysteresis loops open just below 2.2 and 1.8 K, respectively. Thus, heterometallic polymer 1 is the first single-chain magnet involving a pentagonal bipyramidal [Re^IV(CN)₇]³⁻ synthon, and the binuclear complex 2 represents a single-molecule magnet. [ABSTRACT FROM AUTHOR]