Reactivity of coordinatively unsaturated iron complexes towards carbon monoxide: to bind or not to bind?
Reactivity of coordinatively unsaturated iron complexes towards carbon monoxide: to bind or not to bind?
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DOI：
10.1039/c0dt01636e
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发表时间：
2011-01-01
影响因子：
4
通讯作者：
Kirchner, Karl A.
中科院分区：
文献类型：
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作者：
Benito-Garagorri, David;Lagoja, Irene;Kirchner, Karl A.
概述了配位不饱和铁络合物（在大多数情况下为 Fe(II)）对一氧化碳的反应性。已知不饱和铁配合物的配位数(CN)为2至5，分别采用线性或轻微弯曲(CN = 2)、三角形(CN = 3)、四面体、平面正方或三棱锥(CN = 4)、以及四方锥或三方双锥几何形状(CN = 5)。 CO 的结合很大程度上取决于辅助配体的数量和性质（总体配体场强）、配合物的电荷、配合物的几何形状以及不饱和金属中心的自旋状态。在许多情况下，CO 添加到高自旋铁络合物中时，伴随着自旋态的变化，形成处于最低可能自旋态的化合物，即 S=0。然而，在其他几种情况下，CO 的添加是可逆的，甚至由于热力学或动力学原因完全被拒绝。在后一种情况下，此类反应被称为“自旋阻断”或“自旋禁止”。
An overview of the reactivity of coordinatively unsaturated iron complexes (in most cases Fe(II)) towards carbon monoxide is presented. Unsaturated iron complexes are known with coordination numbers (CN) of two to five adopting linear or slightly bent (CN=2), trigonal (CN=3), tetrahedral, square planar or trigonal pyramidal (CN=4), and square-pyramidal or trigonal-bipyramidal geometries (CN=5), respectively. The binding of CO depends strongly on the number and the nature of co-ligands (overall ligand field strength), the charge of the complex, the complex geometry, and the spin state of the unsaturated metal center. In many cases, CO addition to high-spin iron complexes takes place with concomitant spin state changes forming compounds in the lowest possible spin state, i.e., with S=0. In several other cases, however, the addition of CO is reversible or is even totally rejected altogether for either thermodynamic or kinetic reasons. In the case of the latter such reactions are termed "spin-blocked" or "spin forbidden".