Magnetic blocking in a linear iron(I) complex.
Magnetic blocking in a linear iron(I) complex.
复制标题
DOI：
10.1038/nchem.1630
复制
发表时间：
2013-07
期刊：
影响因子：
21.8
通讯作者：
Joseph M. Zadrozny;D. Xiao;M. Atanasov;G. Long;F. Grandjean;F. Neese;J. Long
中科院分区：
文献类型：
--
作者：
Joseph M. Zadrozny;D. Xiao;M. Atanasov;G. Long;F. Grandjean;F. Neese;J. Long
包含一个自旋中心的单分子磁体可以代表基于自旋的计算设备的最小可能单位。然而，这样的应用需要通过大的轴向磁各向异性来实现具有自旋反转的大量能量势垒的分子。最近，通过使用镧系元素中心，如铽（iii）和镝（iii），在这方面取得了重大进展，它们的各向异性可以导致极高的弛豫障碍。我们认为，通过保持低配位数来限制d轨道配体场分裂能量的大小（这往往会阻碍大各向异性的发展），过渡金属应该可以实现类似的效果。本文报道了铁(i)的第一个二坐标配合物[Fe (C (SiMe3) 3) 2]−，其交流磁化率测量结果显示，在零直流电场下，其磁弛豫速度低于29 K。该S=配合物具有226 (4)cm−1的有效自旋反转势垒，这是迄今为止观察到的基于过渡金属的单分子磁铁中最大的，并且在4.5 K以下显示出磁阻塞。
Single-molecule magnets that contain one spin centre may represent the smallest possible unit for spin-based computational devices. Such applications, however, require the realization of molecules with a substantial energy barrier for spin inversion, achieved through a large axial magnetic anisotropy. Recently, significant progress has been made in this regard by using lanthanide centres such as terbium (iii) and dysprosium (iii), whose anisotropy can lead to extremely high relaxation barriers. We contend that similar effects should be achievable with transition metals by maintaining a low coordination number to restrict the magnitude of the d-orbital ligand-field splitting energy (which tends to hinder the development of large anisotropies). Herein we report the first two-coordinate complex of iron (i),[Fe (C (SiMe3) 3) 2]−, for which alternating current magnetic susceptibility measurements reveal slow magnetic relaxation below 29 K in a zero applied direct-current field. This S= complex exhibits an effective spin-reversal barrier of U eff= 226 (4) cm− 1, the largest yet observed for a single-molecule magnet based on a transition metal, and displays magnetic blocking below 4.5 K.