ELECTRONIC CONFIGURATION AND STRUCTURE OF PARAMAGNETIC IRON DINITROSYL COMPLEXES
ELECTRONIC CONFIGURATION AND STRUCTURE OF PARAMAGNETIC IRON DINITROSYL COMPLEXES
复制标题
DOI：
10.1139/v92-240
复制
发表时间：
1992-07-01
期刊：
影响因子：
--
通讯作者：
EATON, DR
中科院分区：
文献类型：
--
作者：
BRYAR, TR;EATON, DR
用电子自旋共振、红外光谱和X射线晶体学研究了顺磁性铁二亚硝酰配合物的电子结构和几何结构。它的结论是，这些化合物是最好的描述为17电子配合物与d9配置，而不是d 7配置假定的大多数以前的研究者。的g值的各向异性，从冻结的解决方案的电子自旋共振光谱确定，变化很大，从复杂到复杂。结果与所有配合物都具有畸变四面体几何构型的假设一致，但畸变的性质随着配体的变化而变化。由于这种变化，含自旋d轨道的性质发生了变化。含有硬的、不可极化的供体原子如氧或氟的配体产生朝向平面几何形状的畸变，将奇数电子置于主要d（x2-y2）轨道中，而含有较软的供体原子如磷或硫的配体产生具有不同类型畸变的络合物，导致奇数电子置于主要d（z）2轨道中。氮和卤化物供体配体产生较小的扭曲，导致含有自旋的分子轨道与d轨道的混合物的贡献。根据这个模型，[Fe（NO）2 I2]-的晶体结构被发现只是轻微地从关于铁原子的规则四面体配位扭曲。
The electronic and geometric structures of paramagnetic iron dinitrosyl complexes have been investigated using electron spin resonance, infrared spectroscopy, and X-ray crystallography. It is concluded that these compounds are best described as 17 electron complexes with a d9 configuration rather than the d7 configuration assumed by most previous investigators. The anisotropy of the g values, determined from the electron spin resonance spectra of frozen solutions, varies considerably from complex to complex. The results are consistent with the supposition that all of the complexes have a distorted tetrahedral geometry, but the nature of the distortion changes as the ligands are varied. As a result of this variation there are changes in the nature of the spin-containing d orbital. Ligands containing hard, nonpolarizable donor atoms such as oxygen or fluorine produce a distortion towards a planar geometry, placing the odd electron in a predominantly d(x2-y2) orbital, while those containing softer donor atoms such as phosphorus or sulfur give complexes with a different type of distortion, leading to placement of the odd electron in a predominantly d(z)2 orbital. Nitrogen and halide donor ligands produce smaller distortions, leading to spin-containing molecular orbitals with contributions from a mixture of d orbitals. In accordance with this model, the crystal structure of [Fe(NO)2I2]- has been found to be only slightly distorted from regular tetrahedral coordination about the iron atom.