High and low spin mononuclear and dinuclear iron(II) complexes of 4-amino and 4-pyrrolyl-3,5-di(2-pyridyl)-4H-1,2,4-triazoles.
High and low spin mononuclear and dinuclear iron(II) complexes of 4-amino and 4-pyrrolyl-3,5-di(2-pyridyl)-4H-1,2,4-triazoles.
复制标题
DOI：
10.1021/ic801039j
复制
发表时间：
2008-09
影响因子：
4.6
通讯作者：
Jonathan A. Kitchen;A. Noble;C. D. Brandt;B. Moubaraki;K. Murray;S. Brooker
中科院分区：
文献类型：
--
作者：
Jonathan A. Kitchen;A. Noble;C. D. Brandt;B. Moubaraki;K. Murray;S. Brooker
第一个双核铁（II）配合物的任何4-取代的3，5-二合成了2-吡啶基-4H-1，2，4-三唑配体[Fe（II）2（adpt）2（H2O）1.5（CH 3CN）2.5]（BF 4）4和[Fe（II）2（pldpt）2（H2O）2（CH 3CN）2]（BF 4）4 [其中adpt为4-氨基-3，5-二（2-吡啶基）-4H-1，2，4-三唑和pldpt是4-吡咯基-3，5-二（2-吡啶基）-4H-1，2，4-三唑]。这两个双核配合物的功能双三唑桥铁（II）中心，被发现是[高自旋高自旋]在所有温度下，4-300 K，并表现出弱的反铁磁耦合。在类似的单金属配合物[Fe（II）（Rdpt）2（X）2]（n+）中，铁（II）中心的自旋状态通过适当选择轴向配体X来控制。具体地，发现氯化物络合物[Fe（II）（adpt）2（Cl）2] x 2 MeOH和[Fe（II）（pldpt）2（Cl）2] x 2 MeOH x H2O都是高自旋的，而吡啶加合物[Fe（II）（adpt）2（py）2]（BF 4）2是低自旋的。制备[Fe（II）（pldpt）2（py）2]（BF 4）2和双核类似物[Fe（II）2（Rdpt）2（py）4]（BF 4）4的尝试失败，说明了在尝试开发对从铁（II）和这些双二齿配体的反应获得的产物的性质的控制时所面临的重大挑战。
The first dinuclear iron(II) complexes of any 4-substituted 3,5-di(2-pyridyl)-4H-1,2,4-triazole ligands, [Fe(II)2(adpt)2(H2O)1.5(CH3CN)2.5](BF4)4 and [Fe(II)2(pldpt)2(H2O)2(CH3CN)2](BF4)4, are presented [where adpt is 4-amino-3,5-di(2-pyridyl)-4H-1,2,4-triazole and pldpt is 4-pyrrolyl-3,5-di(2-pyridyl)-4H-1,2,4-triazole]. Both dinuclear complexes feature doubly triazole bridged iron(II) centers that are found to be [high spin-high spin] at all temperatures, 4-300 K, and to exhibit weak antiferromagnetic coupling. In the analogous monometallic complexes, [Fe(II)(Rdpt)2(X)2](n+), the spin state of the iron(II) center was controlled by appropriate selection of the axial ligands X. Specifically, both of the chloride complexes, [Fe(II)(adpt)2(Cl)2] x 2 MeOH and [Fe(II)(pldpt)2(Cl)2] x 2 MeOH x H2O, were found to be high spin whereas the pyridine adduct [Fe(II)(adpt)2(py)2](BF4)2 was low spin. Attempts to prepare [Fe(II)(pldpt)2(py)2](BF4)2 and the dinuclear analogues [Fe(II)2(Rdpt)2(py)4](BF4)4 failed, illustrating the significant challenges faced in attempts to develop control over the nature of the product obtained from reactions of iron(II) and these bis-bidentate ligands.