Crystal field of atypical low-spin ferriheme complexes
Crystal field of atypical low-spin ferriheme complexes
复制标题
DOI：
10.1021/ja00319a041
复制
发表时间：
1984-04
影响因子：
15
通讯作者：
J. Salerno;J. Leigh
中科院分区：
文献类型：
--
作者：
J. Salerno;J. Leigh
最近发现的血红素模型配合物，包括四苯基卟啉铁（Ⅲ）和原卟啉铁（Ⅲ）的双哌啶和双（2-甲基咪唑）配合物，其电子顺磁共振谱具有异常大的g值。然而，先前对其他q值的赋值是不正确的;这导致了HALS（高度各向异性低自旋）复合物的单独类别的产生。正确分配的g值导致一个晶体场模型中的低自旋复合物都属于一个单一的连续类别。对于所谓的HALS物质，I的值仅较小，主要是由于V的降低。双（2-甲基咪唑）络合物的更轴向性质可能是由于双（咪唑）和双（2-甲基咪唑）络合物之间的平面轴向配体的取向的差异。
Recently reportedheme model complexes including bis (piperidine) and bis (2-methylimidazole) complexes of (tetraphenylporphyrin) iron (III) and (protoporphyrin IX) iron (III) exhibit electron paramagnetic resonance spectra with unusually large values of g. Previous assignments of the other q values were incorrect, however; these led to thecreation of a separate category of HALS (highly anisotropic low spin) complexes. Correct assignment of the g values leads to a crystal field model in which the low-spin complexes all fall into a single continuous category. The values of/are merely smaller for the so-called HALS species, due primarily to a decrease in V. The more axial nature of the bis (2-methylimidazole) complexes may be due to a difference in the orientation of the planar axial ligands between the bis (imidazole) and bis (2-methylimidazole) complexes.