Predictable Substituent Control of Co<sup>III/II</sup> Redox Potential and Spin Crossover in Bis(dipyridylpyrrolide)cobalt Complexes
作者:James N. McPherson、Ross W. Hogue、Folaranmi Sunday Akogun、Luca Bondì、Ena T. Luis、Jason R. Price、Anna L. Garden、Sally Brooker、Stephen B. Colbran
DOI:10.1021/acs.inorgchem.8b03457
日期:2019.2.4
[CoII(dppR1,R2)2] complexes, two of which are structurally characterized at both 100 and 298 K. Both the oxidation and spin states of these complexes can be switched in response to appropriate external stimuli. All complexes, except [CoII(dppMe,Me)2], exhibit gradual spin crossover (SCO) in the solid state, and SCO activity is observed for three complexes in CDCl3 solution. The cobalt(II) centers in the
五个易于制备的三齿三齿单阴离子2,5-二吡啶基-3-(R 1)-4-(R 2)-吡咯化物阴离子(dpp R1,R2)-,其R 1和R 2取代基的性质各不相同[R 1,R 2= CN,Ph;CO 2 Et,CO 2 Et;CO 2 Me,4-Py; CO 2我,我;我 Me,Me]已用于生成类似的中性族[Co II(dpp R1,R2)2]配合物,其中两个在100和298 K上都具有结构特征。这些配合物的氧化态和自旋态都可以响应于适当的外部刺激而切换。除[Co II(dpp Me,Me)2 ]外,所有配合物均呈固态逐渐旋转交叉(SCO),并且在CDCl 3溶液中观察到三种配合物的SCO活性。低自旋(LS)配合物中的钴(II)中心沿吡咯化物-吡咯化物轴呈四边形压缩的Jahn–Teller。高自旋(HS)态的络合物比LS态更失真,SCO活性铁(II)络合物通常也是如此。可逆Co III / II