State Key Laboratory of Structural Chemistry, Fujian Institute of Research on the Structure of Matter, The Chinese Academy of Sciences, Fuzhou, Fujian 350002, China.
Inorg Chem. 2011 Oct 17;50(20):10342-52. doi: 10.1021/ic201403k. Epub 2011 Sep 16.
A family of Mn(III)/Ni(II) heterometallic clusters, [Mn(III)(4)Ni(II)(5)(OH)(4)(hmcH)(4)(pao)(8)Cl(2)]·5DMF (1·5DMF), [Mn(III)(3)Ni(II)(6)(N(3))(2)(pao)(10)(hmcH)(2)(OH)(4)]Br·2MeOH·9H(2)O (2·2MeOH·9H(2)O), Mn(III)Ni(II)(5)(N(3))(4)(pao)(6)(paoH)(2)(OH)(2)·MeOH·3H(2)O (3·MeOH·3H(2)O), and [Mn(III)(2)Ni(II)(2)(hmcH)(2)(pao)(4)(OMe)(2)(MeOH)(2)]·2H(2)O·6MeOH (4·2H(2)O·6MeOH) [paoH = pyridine-2-aldoxime, hmcH(3) = 2, 6-Bis(hydroxymethyl)-p-cresol], has been prepared by reactions of Mn(II) salts with [Ni(paoH)(2)Cl(2)], hmcH(3), and NEt(3) in the presence or absence of NaN(3) and characterized. Complex 1 has a Mn(III)(4)Ni(II)(5) topology which can be described as two corner-sharing [Mn(2)Ni(2)O(2)] butterfly units bridged to an outer Mn atom and a Ni atom through alkoxide groups. Complex 2 has a Mn(III)(3)Ni(II)(6) topology that is similar to that of 1 but with two corner-sharing [Mn(2)Ni(2)O(2)] units of 1 replaced with [Mn(3)NiO(2)] and [MnNi(3)O(2)] units as well as the outer Mn atom of 1 substituted by a Ni atom. 1 and 2 represent the largest 3d heterometal/oxime clusters and the biggest Mn(III)Ni(II) clusters discovered to date. Complex 3 possesses a MnNi(5)(μ-N(3))(2)(μ-OH)(2) core, whose topology is observed for the first time in a discrete molecule. Careful examination of the structures of 1-3 indicates that the Mn/Ni ratios of the complexes are likely associated with the presence of the different coligands hmcH(2-) and/or N(3)(-). Complex 4 has a Mn(III)(2)Ni(II)(2) defective double-cubane topology. Variable-temperature, solid-state dc and ac magnetization studies were carried out on complexes 1-4. Fitting of the obtained M/(Nμ(B)) vs H/T data gave S = 5, g = 1.94, and D = -0.38 cm(-1) for 1 and S = 3, g = 2.05, and D = -0.86 cm(-1) for 3. The ground state for 2 was determined from ac data, which indicated an S = 5 ground state. For 4, the pairwise exchange interactions were determined by fitting the susceptibility data vs T based on a 3-J model. Complex 1 exhibits out-of-phase ac susceptibility signals, indicating it may be a SMM.
一个 Mn(III)/Ni(II) 杂化簇的家族，[Mn(III)(4)Ni(II)(5)(OH)(4)(hmcH)(4)(pao)(8)Cl(2)]·5DMF（1·5DMF），[Mn(III)(3)Ni(II)(6)(N(3))(2)(pao)(10)(hmcH)(2)(OH)(4)]Br·2MeOH·9H(2)O（2·2MeOH·9H(2)O），Mn(III)Ni(II)(5)(N(3))(4)(pao)(6)(paoH)(2)(OH)(2)·MeOH·3H(2)O（3·MeOH·3H(2)O），和[Mn(III)(2)Ni(II)(2)(hmcH)(2)(pao)(4)(OMe)(2)(MeOH)(2)]·2H(2)O·6MeOH（4·2H(2)O·6MeOH）[paoH=吡啶-2-醛肟，hmcH(3)=2,6-二羟甲基-对甲酚]，通过 Mn(II)盐与[Ni(paoH)(2)Cl(2)]、hmcH(3)和 NEt(3)的反应，在存在或不存在 NaN(3)的情况下制备，并进行了表征。复合物 1 具有 Mn(III)(4)Ni(II)(5)拓扑结构，可以描述为两个通过烷氧基桥连的角共享[Mn(2)Ni(2)O(2)]蝶形单元，通过烷氧基桥连到外部的 Mn 原子和 Ni 原子。复合物 2 具有类似于 1 的 Mn(III)(3)Ni(II)(6)拓扑结构，但 1 中的两个角共享[Mn(2)Ni(2)O(2)]单元被[Mn(3)NiO(2)]和[MnNi(3)O(2)]单元以及 1 中的外部 Mn 原子被 Ni 原子取代。1 和 2 代表迄今为止发现的最大的 3d 杂金属/肟簇和最大的 Mn(III)Ni(II)簇。复合物 3 具有[MnNi(5)(μ-N(3))(2)(μ-OH)(2)]（9+）核心，其拓扑结构首次在离散分子中观察到。仔细研究 1-3 的结构表明，配合物的 Mn/Ni 比可能与不同的配位体 hmcH(2-)和/或 N(3)(-)的存在有关。复合物 4 具有 Mn(III)(2)Ni(II)(2)有缺陷的双立方烷拓扑结构。对复合物 1-4 进行了变温、固态直流和交流磁化研究。获得的 M/(Nμ(B))与 H/T 数据的拟合给出了 S = 5，g = 1.94，D = -0.38 cm(-1)对于 1 和 S = 3，g = 2.05，D = -0.86 cm(-1)对于 3。2 的基态是通过交流数据确定的，这表明基态为 S = 5。对于 4，根据 3-J 模型拟合磁化率数据确定了成对交换相互作用。复合物 1 表现出反相交流磁化率信号，表明它可能是一个 SMM。
