Reduction of Ferryl Heme by a Nitroxide Radical

This shows a supposed mechanism for the reduction of ferryl heme (a "compound-II-like" species) by a nitroxide radical, thereby forming the oxoammonium cation form of the nitroxide. I was going to use a single bond alongside a dative bond to show the donation of both electrons to a p(sigma)-d(sigma) bonding or antibonding orbital by oxygen, as suggested by Everse (1998) (see yesterday's postings), but the program wouldn't let me do that. I added a partial (delta) symbol to the formal charges instead, to try to convey the uncertainty about the electron configuration.