Single molecule magnet: Heterodinuclear cyano-bridged cubic cluster [(Tp)8Fe4Ni4(CN)12] (Tp = hydrotris(1-pyrazolyl)borate)

The octanuclear cyano-bridged cluster [(Tp)8Fe4Ni4(CN)12] · H2O · 24CH3CN (1) (Tp = hydrotris(1-pyrazolyl)borate) showing magnetic properties of single-molecule magnet has been synthesized by reaction of [fac-Fe(Tp)(CN)3]− with {(Tp)Ni(NO3)} species formed from an equimolar reaction mixture of Ni(NO3)2 · 6H2O and KTp in MeCN. The X-ray analysis of 1 shows molecular cube structure in which FeIII and NiII ions reside in alternate corners. The average intramolecular Fe⋯Ni distance is 5.124 Å. Out-of-phase ac susceptibility and reduce magnetization measurements show that 1 is a single molecule magnet with ground spin state S = 6 and spin reversal energy barrier U = 14 K. Magnetic hysteresis loops were also observed by applying fast sweeping field.