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

我们观察到，在以下两个体系中，铁的电子构型随着卟啉环形变的增加而由通常的(Dxy)^2(dxz，dyz)^3变为反常的(dxz，dyz)^4(Dxy)^1。乙基络合物的结晶学分析表明，该卟啉环具有很强的S褶皱。未取代络合物中吡咯质子的~1H核磁共振信号在正常的高场区域表现为低自旋络合物，而烷基取代络合物的~1H核磁共振信号则在相当低的场下观察到。特别是在异丙基络合物中，吡咯信号出现在所谓的“抗磁区”。此外，异丙基配合物的EPR谱显示出不同寻常的“轴型”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，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。合成了一系列双(氰基)(中位-四烷基卟啉铁(III))配合物，其中R=H，Me，Et，和IPR，并用1HNMR，^&lt；13&gt；C-核磁共振和EPR谱进行了表征。未取代的配合物(R=H)的光谱结果与典型的低自旋配合物相似，而烷基取代的配合物的光谱结果却截然不同；吡咯1H和氰化物~(13)&GT；C的顺磁位移很小。与核磁共振结果相对应的是，烷基取代络合物的EPR给出了不寻常的“轴型”谱，而不是通常的“大GMAX型”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(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.