Wang Li-Xin, Wu Xiao-Fan, Jin Xin-Xin, Li Jia-Yi, Wang Bing-Wu, Liu Ji-Yan, Xiang Jing, Gao Song
Key Laboratory of Optoelectronic Chemical Materials and Devices (Ministry of Education), School of Optoelectronic Materials and Technology, Jianghan University, Wuhan, 430056, China.
College of Chemistry and Environmental Engineering, Yangtze University, Jingzhou 434020, Hubei, P. R. China.
Dalton Trans. 2023 Oct 24;52(41):14797-14806. doi: 10.1039/d3dt02307a.
The design and synthesis of high-spin Mn(II)-based single-molecule magnets (SMMs) have not been well developed to a great extent, as compared with a large number of SMMs based on the other first row transition metal complexes. In light of our success in designing Fe(II), Co(II) and Fe(III)-based SMMs with a high coordination number of 8, it is of great interest to design Mn(II) analogues with such a strategy. In this contribution, four Mn(II) compounds, Mn(Ln) (1-4) were obtained from reactions of neutral tetradentate ligands, L1-L4, with hydrated Mn(ClO) (L1 = 2,9-bis(carbomethoxy)-1,10-phenanthroline, L2 = 2,9-bis(carbomethoxy)-2,2'-dipyridine, L3 = ,-dibutyl-1,10-phenanthroline-2,9-dicarboxamide, L4 = 6,6'-bis(2-(tert-butyl)-2-tetrazol-5-yl)-2,2'-bipyridine). Their crystal structures have been determined by X-ray crystallography and it clearly shows that the Mn(II) centers in these compounds have an oversaturated coordination number of 8. Their magnetic properties have been investigated in detail; to our surprise, all of these Mn(II) compounds show interesting slow magnetic relaxation behaviors under an applied direct current field, although they have very small negative values.
与大量基于其他第一行过渡金属配合物的单分子磁体（SMMs）相比，基于高自旋Mn（II）的单分子磁体的设计和合成在很大程度上尚未得到充分发展。鉴于我们成功设计出具有高配位数8的基于Fe（II）、Co（II）和Fe（III）的SMMs，采用这种策略设计Mn（II）类似物具有很大的吸引力。在本论文中，通过中性四齿配体L1-L4与水合Mn（ClO）反应得到了四种Mn（II）化合物Mn（Ln）（1-4）（L1 = 2,9-双（甲氧羰基）-1,10-菲咯啉，L2 = 2,9-双（甲氧羰基）-2,2'-联吡啶，L3 = ，-二丁基-1,10-菲咯啉-2,9-二甲酰胺，L4 = 6,6'-双（2-（叔丁基）-2-四唑-5-基）-2,2'-联吡啶）。通过X射线晶体学确定了它们的晶体结构，结果清楚地表明这些化合物中的Mn（II）中心具有过饱和的配位数8。对它们的磁性进行了详细研究；令我们惊讶的是，所有这些Mn（II）化合物在施加直流磁场下都表现出有趣的慢磁弛豫行为，尽管它们的负值非常小。
