XAS STUDIES OF CPD I INTERMEDIATES

我们收集了11个铁卟啉的Fe K-Edge XAS光谱 化合物和cpd I模型[FeIV=O（TMP*）]+，以便将化合物与化合物之间的相互作用联系起来。 1 s->3d前边缘的强度和多重态分裂图案 区域的几何结构和电子结构的铁网站。 所研究的铁卟啉可分为四类：（1） 6-坐标（低自旋）S=1/2;（2）5坐标（高自旋）S=5/2;（3） 5-坐标（自旋混合）S=5/2-3/2;（4）6-坐标（自旋混合） 混合）S=5/2-3/2。 我们的研究结果最终表明， 观察到的前边缘特征的强度是这些特征的诊断。 四个班。 六坐标的详细多重峰分析， 低自旋复合物[FeTMBPP]Cl允许实验性的 单电子Fe配体场态能量的测定。 到 据我们所知，这是第一次直接测量 铁卟啉的配位场参数。 有趣的是 前边缘区域的信息内容与前边缘区域的信息内容互补 可通过EPR光谱法获得。 这些方法的推广 应该考虑到详细的几何和电子结构 关于EPR沉默亚铁卟啉的信息。

We have collected Fe K-Edge XAS spectra for 11 ferric porphyrin compounds and the cpd I model [FeIV=O(TMP*)]+ in order to relate the intensity and multiplet splitting pattern of the 1s->3d pre-edge region to the geometric and electronic structure of the iron site. The ferric porphyrins studied fall into four categories: (1) 6-coordinate (low-spin) S=1/2; (2) 5-coordinate (high-spin) S=5/2; (3) 5-coordinate (spin admixed) S=5/2-3/2; (4) 6- coordinate (spin admixed) S=5/2-3/2. Our results conclusively show that the integrated intensity of the observed pre-edge features is diagnostic of these four classes. A detailed multiplet analysis of the 6-coordinate, low-spin complex [FeTMBPP]Cl has allowed for an experimental determination of the one-electron Fe ligand field state energies. To our knowledge, this represents the first direct measurement of the ligand field parameters for a ferric porphyrin. Interestingly, the information content of the pre-edge region is complementary to that obtainable by EPR spectroscopy. Extension of these methodologies should allow for detailed geometric and electronic structural information to be obtained on EPR silent ferrous porphyrins.