State Key Laboratory of Coordination Chemistry, School of Chemistry and Chemical Engineering, Collaborative Innovation Center of Advanced Microstructures, Nanjing University, Nanjing 210023, China.
Jiangsu Key Laboratory for NSLSCS, School of Physical Science and Technology, Nanjing Normal University, Nanjing 210023, China.
Dalton Trans. 2018 Dec 28;47(48):17211-17215. doi: 10.1039/c8dt04157a. Epub 2018 Nov 28.
The redox non-innocent ligand 2,2'-bipyrimidine (bpym) reacted with two molar equivalents of LCo(tol) (L = CH(MeC[double bond, length as m-dash]NAr), Ar = 2,6-iPrCH) to afford the binuclear Co complex (LCo)(μ-bpym) (1), in which the bpym moiety accepts two electrons from the metal centers and in the dianion state. Complex 1 readily underwent one-electron oxidation when treated with [CpFe][BPh] affording the cation salt [(LCo)(μ-bpym)][BPh] (2) with the bpym moiety in the radical anion state. Meanwhile, complex 2 could be converted back to 1 with elemental potassium. The magnetic studies revealed that complex 2 is a single molecular magnet (SMM) under a small external field, while 1 has no SMM activity. This represents a new example of a SMM exhibiting a fully reversible 'on/off' switching ability in anodic and neutral states.
氧化还原非配位配体 2,2'-联吡啶(bpym)与两摩尔当量的 LCo(tol)（L = CH(MeC[双键，长度为破折号]NAr)，Ar = 2,6-iPrCH)反应，得到双核 Co 配合物（LCo)(μ-bpym)（1），其中 bpym 部分从金属中心接受两个电子，并处于二阴离子态。当用 [CpFe][BPh]处理时，配合物 1 很容易发生单电子氧化，生成 bpym 部分处于自由基阴离子态的阳离子盐[(LCo)(μ-bpym)][BPh]（2）。同时，用元素钾可以将 2 转化回 1。磁性研究表明，在小外场下，配合物 2 是一个单分子磁体（SMM），而 1 没有 SMM 活性。这代表了一个新的例子，即在阳极和中性状态下具有完全可逆的“开/关”开关能力的 SMM。
