Characterization of a Six-Coordinate Ferrous High-Spin Heme with Both Intramolecular Axial Carboxylic Acid and Pyridine

Synthesis of a bis-strapped porphyrin with a pyridyl residue on one side and a malonic acid on the other side gives after iron(II) insertion a six-coordinate complex in which both apical groups are the two axial ligands of the iron atom. Unexpectedly, this six-coordinate iron(II) complex proves to be high-spin, likely due to some stabilization of the axial metal−ligand antibonding orbitals.

合成一种具有一侧吡啶基团和另一侧富马酸基团的二联吡啶类卟啉，经过铁(II)插入反应后，形成了一个六配位的复杂结构，其中两个顶点基团均为铁原子的轴向配体。令人意外的是，该六配位的铁(II)复杂结构表现出高自旋特性，这可能是由于轴向金属-配体反键轨道的某些稳定化作用所致。