A peroxo- ligand in this coordination complex is degraded to a single redox-active oxygen atom in “compound I” (“compound one”), which goes on to hydroxylate C-H bonds. Unlike typical square planar complexes, this complex’s d-z-squared orbital lies above the d-sub-xy orbital in energy due to repulsion from a proximal histidine. This complex’s transition from a high-spin domed configuration to a low-spin planar configuration corresponds to a larger system’s T state and (*) R state. (10[1])This cofactor for cytochrome P450s is metabolized to a “verdo-“ form before being cleaved to form biliverdin and then excreted (10[1])as bilirubin. Due to pi backbonding, this complex undesirably binds very strongly to CO. (10[1]-5[2])For 10 (10[1]-5[1])points, name this iron-porphyrin (10[1])complex, (-5[1])four of which appear in a namesake protein (-5[1])that binds molecular oxygen in red blood cells. ■END■ (10[3]0[4])