Structural and spectroscopic evidence for linkage isomerism of bound nitrite in a {Fe-NO}6 nitrosyl derived from a tetradentate dicarboxamide ligand: More parallels between heme and non-heme systems

Reaction of NO with [(Me2bpb)Fe(py)2]+ in acetonitrile affords both N- and O-bound NO2-isomers [(Me2bpb)Fe(NO)(NO2)] and [(Me2bpb)Fe(NO)(ONO)]. Formation of both isomers is reminiscent of iron-porphyrin chemistry and indicates small difference in binding energy of the NO2 ligand via N- and O-center to the {Fe-NO}6 moiety.