Author/Authors :
Jones، نويسنده , , Leigh F. and Cochrane، نويسنده , , Martyn E. and Koivisto، نويسنده , , Bryan D. and Leigh، نويسنده , , David A. and Perlepes، نويسنده , , Spyros P. and Wernsdorfer، نويسنده , , Wolfgang and Brechin، نويسنده , , Euan K.، نويسنده ,
Abstract :
We report the synthesis and magnetic properties of three hexametallic Mn clusters: [Mn6O2(Et-sao)6(O2C-Naphth)2(EtOH)4(H2O)2] (1) (HO2C-Naphth = 1-naphthoic acid, Et-saoH2 = 2-hydroxyphenylpropanone oxime), [Mn6O2(Et-sao)6(O2C-Anthra)2(EtOH)4(H2O)2] · 0.66EtOH · 0.33H2O (HO2C-Anthra = anthracene-9-carboxylic acid) (2 · 0.66EtOH · 0.33H2O) and [Mn6O2(Et-sao)6(O2CPhCCH)2(EtOH)4(H2O)2] · 1.7EtOH · 0.3H2O (HO2CPhC CH = 4-ethynylbenzoic acid) (3 · 1.7EtOH · 0.3H2O). Clusters 1–3 exhibit ferromagnetic exchange between all six MnIII centres resulting in S = 12 ground spin states. Ac magnetic susceptibility and single crystal micro-SQUID measurements on 1–3 confirm SMM behaviour with barriers to magnetisation reversal of 60.12 (1), 60.10 (2) and 66.79 (3) K.
Keywords :
Clusters , X-ray structures , Single-molecule magnets , hysteresis , Manganese , magnetism