A cyano-bridged FeIIReIV(CN)2 cluster incorporating two high-magnetic anisotropy building units
作者:T. David Harris、Han Sen Soo、Christopher J. Chang、Jeffrey R. Long
DOI:10.1016/j.ica.2010.12.010
日期:2011.4
The pentagonal bipyramidal high-spin iron(II) complex, [(TPA(2C(O)NHtBu))Fe(CF3SO3)](+), is shown to exhibit a high-anisotropy ground state, with fits to dc magnetization data providing an axial zero-field splitting parameter of D = -7.9 cm (1). The utility of this compound as a building unit is demonstrated, as its reaction with [ReCl4(CN)(2)](2) affords the cyano-bridged dinuclear cluster (TPA(2C(O)NHtBu))FeRCl4(CN)(2). dc magnetic susceptibility measurements reveal intracluster ferromagnetic exchange interactions between Fe-II and Re-IV centers, with J = +3.0 cm (1), giving rise to a spin ground state of S = 7/2. Moreover, fits to dc magnetization data obtained for the FeRe cluster show the presence of strong axial anisotropy, with D = -2.3 cm (1). Finally, variable-frequency ac susceptibility measurements reveal the onset of slow magnetic relaxation at low temperature, suggesting that the FeRe cluster is a single-molecule magnet. (C) 2010 Elsevier B.V. All rights reserved.