Synthesis, properties, and reactivities of nonplanar ferric porphyrin complexes carrying rotationally coordinated axial ligands.

我们观察到，在以下两种体系中，随着卟啉环变形的增加，铁的电子构型从通常的（dxy）^2(dxz, dyz)^3变为异常的（dxz, dyz）^4(dxy)^1。制备了一系列双咪唑（中-四烷基卟啉铁（III））配合物，其中R=Me， Et和iPr。乙基配合物的结晶学分析表明，卟啉环是高度S_4皱褶的。未取代配合物中吡咯质子的^1H核磁共振信号以低自旋配合物的形式出现在正常的高场区，而烷基取代配合物的^1H核磁共振信号则出现在相当低的场区。特别是在异丙基配合物中，吡咯信号出现在所谓的“抗磁区”。此外，异丙基配合物的EPR表现出不同寻常的“轴向型”光谱。根据这些结果，我们得出结论，随着卟啉环非平面性的增加，这些配合物中铁的电子构型从通常的（dxy）^2(dxz, dyz)^3转变为不寻常的（dxz, dyz）^4(dxy)^1。制备了一系列的二（氰化物）（中-四烷基卟啉铁（III））配合物，其中R=H,Me， Et和iPr，并通过^1H NMR，^<13>C NMR和EPR谱进行了检测。未取代配合物（R=H）的光谱结果与典型低自旋配合物相似，而烷基取代配合物的光谱结果则大不相同；吡咯1H和氰化物^<13>C信号显示出相当小的顺磁位移。与核磁共振结果相对应，烷基取代配合物的EPR呈现异常的“轴向型”谱，而不是通常的“大gmax型”谱。基于这些结果，我们得出结论，随着卟啉环非平面性的增加，这些配合物中铁的电子构型从（dxy）^2(dxz, dyz)^3变为（dxz, dyz）^4(dxy)^1。

We have observed that the electon configuration of iron in ferric porphyrin complexes changes from the usual (dxy)^2(dxz, dyz)^3 to unusual (dxz, dyz)^4(dxy)^1 as the deformation of the porphyrin ring increases in the following two systems.A series of bis (imidazole) (meso-tetraalkylporphyrinatoiron (III)) complexes, where R=Me, Et, and iPr, have been prepared. The crystallographic analysis of the ethyl complex has revealed that the porphyrin ring is highly S_4 ruffled. While the ^1H NMR signal of the pyrrole protons in the unsubstituted complex appears at a normal high field region as a low spin complex, those of the alkyl substituted complexes are observed at rather low field. Particularly in the isopropyl complex, the pyrrole signals appear at so called "diamagnetic region". Furthermore, the EPR of the isopropyl complex shows unusual "axial type" spectra. Based on these results, we concluded that the electronic configuration of iron in these complexes changes from the usual (dxy)^2(dxz, dyz)^3 to the unusual (dxz, dyz)^4(dxy)^1 as the nonplanarity of the porphyrin ring increases.A series of bis (cyanide) (meso-tetraalkylporphyrinatoiron(III)) complexes, where R=H,Me, Et, and iPr, have been prepared and examined by ^1H NMR,^<13>C NMR,and EPR spectra. While the unsubstituted complex (R=H) showed spectropic results similar to those of the typical low spin complexes, the alkyl substituted complexes exhibited quite different results ; pyrrole 1H and cyanide ^<13>C signals showed rather small paramagnetic shifts. Corresponding to the NMR results, the EPR of the alkyl substituted complexes gave the unusual "axial type" spectra instead of the usual "large gmax type" spectra. Based on these results, we concluded that the electronic configuration of iron in these complexes changes from (dxy)^2(dxz, dyz)^3 to (dxz, dyz)^4(dxy)^1 as the nonplanarity of the porphyrin ring increases.