Metal Oxidation Promoted C−H Activation in Manganese Complexes of N-Confused Porphyrin

The N-confused porphyrin complex Mn(II)(NCHPP)Br exhibits a nonplanar porphyrin ring with an inner core C-H on the inverted pyrrole ring. The aerobic metal oxidation promotes the dissociation of an inner-core proton on the inverted pyrrole ring and changes the N-confused porphyrin conformation to a planar porphyrin ring to form Mn(III)(NCPP)Br. The conjugate systems and metal oxidation states are confirmed by crystal structures as well as spectroscopic data. The reverse reaction can be achieved by treating the Mn(III)(NCPP)Br with p-toluenesulfonhydrazide.