Unusual Mn5 cluster with a ‘twisted bow-tie’ topology and MnIIMnIII2MnIV2 oxidation states: Synthesis, structure, and magnetic properties
Unusual Mn5 cluster with a ‘twisted bow-tie’ topology and MnIIMnIII2MnIV2 oxidation states: Synthesis, structure, and magnetic properties
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DOI：
10.1016/j.poly.2021.115141
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发表时间：
2021-03
期刊：
影响因子：
2.6
通讯作者：
Ashlyn R. Hale;Philippa King;K. Abboud;G. Christou
中科院分区：
文献类型：
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作者：
Ashlyn R. Hale;Philippa King;K. Abboud;G. Christou
涉及MnO4-在甲醇中在羧酸存在下反应的“还原聚集”过程首次扩展到使用二元酸和附加存在的螯合物，即邻苯二甲酸(PhthH2)和2，2‘-联吡啶(Bpy)。在甲醇中，MnO4-：phthH2：bpy=1：2：1反应得到了[Mn5O4(Phth)3(PhthH)(Bpy)4](PhthH2)(PhthH)(PhthH)(1)，其Mn5阳离子具有由两个近垂直的MnII，III，IV3scalene三角形组成的扭曲的蝴蝶结拓扑结构。每个三角形由一个中心μ3-O2-和一个位于MnIIIMnIV边缘的μ2-O2-连接。周边连接是由邻苯二甲酸酯基团以各种方式桥联，并在每个MnIII和MnIV离子上螯合BPY来实现的。该阳离子是一个具有三个锰氧化态的簇合物的罕见例子，也是第一个含有MnIV的邻苯二甲酸盐络合物。在5.0K-300K范围内，对在0.1T磁场中收集的变温固态直流磁化率数据进行了拟合J1=J(MnIIIMnIV)1，J2=J(−)116(3)cm−1，J2=J(MnIIMnIV)−=(4)cm−1，J3=J(MnIMnIII)=+3.8(8)cm−1，g=11.95，尖端−=约500cm1×10-6cm3mo1，这表明ANS=7/2自旋基态，这一点得到了在0.1-7.0T和1.8-10.0K范围内收集的磁化数据的拟合，以及在1000 GHz频率下的零直流磁场和3.5G交流磁场下的交流同相磁化率数据的证实。
The ‘reductive aggregation’ procedure involving the reaction of MnO4-in MeOH in the presence of a carboxylic acid has been extended for the first time to the use of a dicarboxylic acid and the additional presence of a chelate, namely phthalic acid (phthH2) and 2,2′-bipyridine (bpy), respectively. The MnO4-:phthH2:bpy = 1:2:1 reaction in MeOH has led to isolation of [Mn5O4(phth)3(phthH)(bpy)4](phthH2)(phthH) (1), whose Mn5cation possesses a ‘twisted bow-tie’ topology comprising two near-perpendicular MnII,III,IV3scalene triangles fused at the MnIIion. Each triangle is bridged by a central μ3-O2-and a μ2-O2-on the MnIIIMnIVedge. Peripheral ligation is provided by the phthalate groups bridging in various modes, and a chelating bpy on each MnIIIand MnIVion. The cation is a rare example of a cluster with three Mn oxidation states, and it is also the first MnIV-containing phthalate complex. Fitting of variable-temperature, solid-state dc magnetic susceptibility data collected in a 0.1 T field in the 5.0–300 K range gaveJ1=J(MnIIIMnIV) = − 116(3) cm−1,J2=J(MnIIMnIV) = − 6.0(4) cm−1,J3=J(MnIIMnIII) = +3.8(8) cm−1, andg= 1.95, with TIP = 500 × 10-6cm3mol−1. These indicate anS=7/2spin ground state, which was confirmed by a fit of magnetization data collected in the 0.1–7.0 T and 1.8–10.0 K ranges, and by ac in-phase susceptibility data in zero dc field and a 3.5 G ac field at a 1000 Hz frequency.