Two novel mixed valence Co^II–Co^III complexes, namely [Co^IICo^III(L1)(ab)(mb)₂(H₂O)]·dmf (1) and [Co^III₂Co^II(L2)₄(H₂O)₄]·2H₂O (2) [H₂L1 = (E)-2-((1-hydroxybutan-2-ylimino)methyl)-6-methoxyphenol, ab = 2-amino-butan-1-ol anion, mb = p-methyl benzoate, H₂L2 = 3-((2-hydroxy-3-methoxy-benzylidene)-amino)-propionic acid, and dmf = N,N-dimethyl-formamide], were synthesized and characterized by single crystal X-ray diffraction and magnetic studies at low temperature. The structure determination reveals that both complexes belong to the monoclinic system with P21/c (1) and I2/a (2) space groups. Complex 1 is a dinuclear Co^IIICo^II compound with distorted octahedral cobalt centers showing different coordination environments. In 2, a bent trinuclear Co^III₂Co^II complex, the coordination environments around the two terminal Co^III sites are alike, whereas they are different in the central Co^II ion. Alternating current/direct current (ac/dc) magnetic studies revealed that both complexes show field-induced slow magnetic relaxation. The dc magnetic susceptibility and magnetization data were analyzed with the following Hamiltonianwhere D and E are the axial and rhombic zero-field splitting (zfs) parameters, respectively, and a good agreement between experimental and simulated results was found using the parameters g_⊥ = 2.585, g_∥ = 2.437, D = +98.1 cm⁻¹, E/D = 0.008 and F = 8.2× 10⁻⁵ for 1 and g_⊥ = 2.580, g_∥ = 2.580, D = +55.4 cm⁻¹, and E/D = 0.000 for 2.

中文翻译：

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混合价二核和三核CoII-CoIII配合物的磁场诱导的慢磁弛豫。

两种新颖的价态的Co ^II - Co ^III配合物，即[Co ^II Co ^III（L1）（ab）（mb）₂（H ₂ O）]·dmf（1）和[Co ^III ₂ Co ^II（L2）₄（ H ₂ O）₄ ]·2H ₂ O（2）[H ₂ L1 =（E）-2-（（（1-羟丁-2-亚氨基）甲基）-6-甲氧基苯酚，ab = 2-氨基-丁-1 -ol阴离子，mb =对-苯甲酸甲酯，H ₂ L2 = 3-（（2-羟基-3-甲氧基-亚苄基）-氨基）-丙酸，dmf = N，ñ -二甲基-甲酰胺]，被合成和表征通过单晶X射线衍射，并在低温磁性研究。结构确定表明，两个复合物均属于具有P 21 / c（1）和I 2 / a（2）空间群的单斜系统。配合物1是一种双核Co ^III Co ^II化合物，具有扭曲的八面体钴中心，显示出不同的配位环境。在2，弯曲三核钴^III ₂钴^II络合物，围绕两个端子Co的配位环境^III位相似，但中心Co ^II离子不同。交流/直流（ac / dc）磁学研究表明，两种配合物均显示出场感应的慢磁弛豫。使用以下哈密顿量分析直流磁化率和磁化数据其中d和Ë是轴向和菱形零场分裂（ZFS）参数，分别与实验和模拟结果之间具有良好的一致性，使用的参数找到克_⊥ = 2.585，克_∥ = 2.437，d =98.1厘米^{- 1}，Ë / d = 0.008和˚F = 8.2×10 ^-5对1和克_⊥ = 2.580，克_∥ = 2.580，d =55.4厘米^-1，和ë / d = 0.000为2。