Rare nuclearities in Mn/oxo cluster chemistry: Synthesis and characterization of a mixed-valence {MnII/III11} complex bearing acetate and salicylhydroximate(-3) bridging/chelating ligands
Rare nuclearities in Mn/oxo cluster chemistry: Synthesis and characterization of a mixed-valence {MnII/III11} complex bearing acetate and salicylhydroximate(-3) bridging/chelating ligands
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DOI：
10.1016/j.poly.2021.115298
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发表时间：
2021-05
期刊：
影响因子：
2.6
通讯作者：
E. Koumousi;Gerasimi Lazari;S. Grammatikopoulos;Constantina Papatriantafyllopoulou;M. Manos;S. Perlepes;A. Tasiopoulos;G. Christou;T. Stamatatos
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文献类型：
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作者：
E. Koumousi;Gerasimi Lazari;S. Grammatikopoulos;Constantina Papatriantafyllopoulou;M. Manos;S. Perlepes;A. Tasiopoulos;G. Christou;T. Stamatatos
Mn（O2 CMe）2·4 H2O、水杨基异羟肟酸（shaH 2）和Me 4 NOH·5 H2O（摩尔比2：1：2）在乙腈和甲醇混合溶剂中一锅法合成了新的混合价簇合物（Me 4 N）4[MnII 2 MnIII 9 O 4（O2 CMe）9（shi）6]（1）。四齿（N，O，O，O）螯合/桥连配体shi 3 −的阴离子是由shaH 2的原位金属离子辅助的酰胺-亚氨醇互变异构产生的。1的[MnII 2 MnIII 9（μ3-O）4（μ-OR）3（μ3-NO）6]14+核由四个不同类型的顶点共享{MnIII 3（μ3-O2-）}7+三角形亚基组成，它们分别通过六个η1：η 1：η1：η2：μ 3shi 3-和三个η1：η2：μ 3 MeCO 2-基团的肟基臂和羧酸根O原子相互连接。围绕核心的外围连接由六个η1：η1：μ MeCO 2 −基团和shi 3 −配体的螯合部分提供。固态直流（dc）磁化率研究揭示了Mn中心之间存在主要的反铁磁交换相互作用，这主要是由{Mn 3}三角形平面内μ3-O2−的共面性和Mn单键N单键O单键Mn桥接单元的微小畸变促进的。低激发态排除了从磁化数据中获得良好拟合，而基态则是从交流（ac）数据中确定的，这表明1的S = 3基态。结合的结果强调了从使用水杨基氢肟螯合/桥接配体的非常罕见的核和美丽的分子结构的新的3d-金属簇的持续供应。
The one-pot reaction between Mn(O2CMe)2·4H2O, salicylhydroxamic acid (shaH2) and Me4NOH·5H2O in a molar ratio of 2:1:2, and a solvent mixture comprising MeCN and MeOH, affords the new mixed-valence cluster compound (Me4N)4[MnII2MnIII9O4(O2CMe)9(shi)6] (1) in moderate yields. The anion of the tetradentate (N,O,O,O) chelating/bridging ligand shi3−resulted from the in-situ metal ion-assisted amide-iminol tautomerism of shaH2. The [MnII2MnIII9(μ3-O)4(μ-OR)3(μ3-NO)6]14+core of1comprises four vertex-sharing {MnIII3(μ3-O2−)}7+triangular subunits of different types, which are linked to each other and the MnIIatoms through the oximato arms and the carboxylate O-atoms of six η1:η1:η1:η2:μ3shi3−and three η1:η2:μ3MeCO2−groups, respectively. Peripheral ligation about the core is provided by six η1:η1:μ MeCO2−groups and the chelating parts of the shi3−ligands. Solid-state direct-current (dc) magnetic susceptibility studies revealed the presence of predominant antiferromagnetic exchange interactions between the Mn centers, mainly promoted by the coplanarity of the μ3-O2−within the {Mn3} triangular planes and the insignificant distortion of the Mnsingle bondNsingle bondOsingle bondMn bridging units. Low-lying excited states precluded obtaining a good fit from the magnetization data, and the ground state was instead determined from the alternating-current (ac) data, which indicated anS= 3 ground state for1. The combined results emphasize the continuing supply from the use of the salicylhydroxime chelating/bridging ligand of new 3d-metal clusters of very rare nuclearities and beautiful molecular structures.