Chair-Shaped MnII2LnIII4 (Ln = Gd, Tb, Dy, Ho) Heterometallic Complexes Assembled from a Tricompartmental Aminobenzohydrazide Ligand

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• 作者：Amit Chakraborty ; Prasenjit Bag ; Joydeb Goura ; Arun Kumar Bar ; Jean-Pascal Sutter ; Vadapalli Chandrasekhar
• 刊名：Crystal Growth & Design
• 出版年：2015
• 出版时间：February 4, 2015
• 年：2015
• 卷：15
• 期：2
• 页码：848-857
• 全文大小：622K
• ISSN：1528-7505

文摘

The reaction of a new compartmental ligand, H₃L [H₃L = N鈥?(2-hydroxy-3-methoxybenzylidene)-2-(-2-hydroxy-3-methoxybenzylideneamino)benzohydrazide], with lanthanide salts followed by reaction of Mn^II salts in presence of triethylamine along with pivalic acid afforded heterometallic hexanuclear complexes, [{LMn(Cl)(渭₃-OH)Gd₂(渭₃-OH)(渭-Piv)₂}₂路3MeCN路7MeOH路H₂O] (1), [{LMn(Cl)(渭₃-OH)Tb₂(渭₃-OH)(渭-Piv)₂}₂路8MeCN] (2), [{LMn(Cl)(渭₃-OH)Dy₂(渭₃-OH)(渭-Piv)₂}₂路2Et₂O路4MeCN路3H₂O] (3), and [{LMn(Cl)(渭₃-OH)Ho₂(渭₃-OH)(渭-Piv)₂}₂路8MeCN] (4). All of the complexes are isostructural, in which two trianionic ligands [L^{3鈥?/sup>] hold the six metal ions, affording a chair-shaped hexametallic core. The asymmetric unit contains half of the molecule, where Mn(II) ions occupy the inner coordination pocket of the ligand in a distorted square pyramidal geometry (NO₃Cl) and the two lanthanide ions occupy the two outer-coordination pockets. Magnetic measurements reveal that antiferromagnetic interactions take place in complexes 1, 3, and 4. On the other hand, complex 2 shows the presence of ferromagnetic interactions.}