An isoelectronic NO dioxygenase reaction using a nonheme iron(iii)-peroxo complex and nitrosonium ion

Abstract

Reaction of a nonheme iron(III)-peroxo complex, [FeIII(14-TMC)(O2)]+, with NO+, a transformation which is essentially isoelectronic with that for nitric oxide dioxygenases [Fe(III)(O2•−) + NO], affords an iron(IV)-oxo complex, [FeIV(14-TMC)(O)]2+, and nitrogen dioxide (NO2), followed by conversion to an iron(III)-nitrato complex, [FeIII(14-TMC)(NO3)(F)]+.

Factors That Control the Reactivity of Cobalt(III)–Nitrosyl Complexes in Nitric Oxide Transfer and Dioxygenation Reactions: A Combined Experimental and Theoretical Investigation

“…These reactions are thought to proceed through Fe III –PN intermediates, prior to nitrate formation; 14,15 nitrogen dioxide (NO 2 ) may otherwise be released. 16 Thus, metal–PN generation may occur via metal–O 2 plus NO or metal–NO plus O 2 reactions, as shown recently in coordination complexes of chromium, 17a,b iron, 17c copper, 18 hemes, 19 and cobalt–porphyrins. 20 …”

“…In relation to the NOD reactivity, TMC chromium–superoxo, chromium–peroxo, and iron–peroxo complexes were treated with NO or nitrosonium (NO + ) ion, and in all cases metal–peroxynitrite intermediates were implicated as transient intermediates, leading to the formation of nitrite or nitrate metal complexes as final products. 17 …”

A Peroxynitrite Dicopper Complex: Formation via Cu–NO and Cu–O2 Intermediates and Reactivity via O–O Cleavage Chemistry

“…This seems to also correspond to known aqueous chemistry: peroxynitrite decomposes through various pathways, 3c,21 , including its degradation according to 2 − OON═O → O 2 + 2NO 2 − under basic conditions and relatively high concentration,s 21b,d,e and such reactivity has even been observed in aqueous chemistry with copper ion. 22 Similarly, Nam and co-workers reported formation of macrocyclic ligand-bound metal−PN complexes, for example, LCr III −PN 23 and non-heme-Fe III −PN 24 species, generated from precursor M−O 2 adducts reacting with NO (g) (Scheme 1). A novel case involves reaction of a macrocyclic ligand (L)Co–nitrosyl complex with potassium superoxide (KO 2 ), leading to LCo III −nitrite + ½ O 2(g) products, all proceeding through putative Co–PN intermediates (Scheme 1).…”

Mechanistic Insight into the Nitric Oxide Dioxygenation Reaction of Nonheme Iron(III)–Superoxo and Manganese(IV)–Peroxo Complexes

“…To mimic NOD reactivity, we recently reported the reactions of superoxide and peroxide complexes of chromium–TMC (TMC = N-tetramethylated cyclam) with NO; the Cr III –peroxo complex [(12-TMC)Cr IV (O 2 )(Cl)] + reacted with NO to form a Cr III –nitrato complex, [15a] whereas a reaction of the Cr III –superoxo complex [(14-TMC)Cr III (O 2 )(Cl)] + and NO gave the Cr IV –oxo complex ([(14-TMC)Cr IV (O)-(Cl)] + ) plus ·NO 2 . [15b] We have also reported a NOD reaction using an Fe III –peroxo complex and nitrosonium ion (NO + ), which produced an Fe III –nitrato complex.…”

“…[15b] We have also reported a NOD reaction using an Fe III –peroxo complex and nitrosonium ion (NO + ), which produced an Fe III –nitrato complex. [15c] …”