Five Disk-Shaped {M^II₇} (M = Mn, Fe, Co, Cu, Zn) Clusters and One Capsule-Like {Cu^II₆Na^I₂} Cluster Assembled from the Same Schiff Base Ligand

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• 作者：Haifeng Zhang ; Jin Zhang ; Rui Liu ; Yahong Li ; Wei Liu and Wu Li
• 刊名：European Journal of Inorganic Chemistry
• 出版年：2016
• 出版时间：September 2016
• 年：2016
• 卷：2016
• 期：26
• 页码：4134-4143
• 全文大小：2577K
• ISSN：1099-0682c

文摘

Six transition-metal clusters of compositions [Mn₇L₆](NO₃)₂·2CH₃OH (1), [Fe₇L₆](NO₃)₂·2CH₃OH (2), [Co₇L₆](NO₃)₂·2CH₃OH (3), [Cu₇L₆](NO₃)₂ (4), [Zn₇L₆](NO₃)₂·2CH₃OH (5), and [Cu₆Na₂L₆](NO₃)₂·4CH₃OH (6) {H₂L = 2-(2-hydroxy-3-methoxybenzylideneamino)phenol} have been synthesized under solvothermal conditions. The structures of 1–6 have been established based on single-crystal X-ray diffraction studies. Complexes 1–5 possess disk-shaped {M^II₇} cores, with the central M^II ion and the six peripheral M^II ions being linked by six µ₃-O atoms. The six M^II ions of the rim of the disk are bridged in a pairwise manner by six µ₂-O atoms. Complex 2 is a very rare example of a disk-shaped {Fe₇} cluster in which all of the Fe atoms exhibit +2 oxidation state. Furthermore, this is the first time that the five isostructural heptanuclear clusters were constructed by using an identical Schiff base ligand. The molecule of complex 6 contains a capsule-like {Cu₆Na₂} core. In this core, two sodium ions reside on the two vertices of the capsule and the 12 vertices of the {Cu₆O₆} hexagonal prism are occupied by alternately arrayed six Cu^II ions and six O atoms. Photoluminescence studies suggest strong emission for 5 in the solid state at room temperature. Variable-temperature dc magnetic susceptibility studies were carried out on polycrystalline samples of 1–4 and 6. The ac susceptibility studies were also performed with 3. Strong out-of-phase, χ′′, signals were observed for 3 at zero field, suggesting that 3 is a class of single molecule magnet (SMM).