Nitric oxide dioxygenation (NOD) reactions of Co^III-peroxo and Ni^III-peroxo complexes: NODversusNO activation

Abstract

Here, we report the nitric oxide dioxygenation (NOD) reactions of NiIII-peroxo, [(12-TMC)NiIII(O22−)]+ (NiIII-O22−, 1), and CoIII-peroxo, [(12-TMC)CoIII(O22−)]+ (CoIII-O22−, 2), complexes bearing N-tetramethylated cyclam (TMC) ligands. The reaction of complex 1...

Oxygen atom transfer promoted nitrate to nitric oxide transformation: a step-wise reduction of nitrate → nitrite → nitric oxide

“…3a and 6a). 19 d ,20 b ,21 a ,27,30,32 Astonishingly, 2 upon reaction with VCl 3 generated corresponding Co III -nitrosyl complex 4, ({CoNO} 8 ), 19 d ,20 b ,21 a ,27,30 with V V -Oxo species in both aqueous/or methanol medium at 298 K ( Scheme 1 ; reaction II). It is important to note that 2 did not show any spectral changes in the absence of VCl 3 , suggesting that 2 is highly stable in H 2 O/or MeOH and at 298 K (ESI, ES, and Fig.…”

“…In the case of NO overproduction, nitric oxide dioxygenase (NODs) generates NO 3 − in the reaction of the iron–dioxygen adduct with NO via a proposed PN intermediate, 19 as explored in other biomimetic systems. 19 d ,20 Also, there are various reports on NO 2 − formation in nitric oxide monooxygenation (NOM) reaction from metal-nitrosyls in the presence of O 2 , O 2 ˙ − and OH − .…”

Hydrogen Bonding Effect on the Oxygen Binding and Activa-tion in Cobalt(III)-peroxo Complexes

“…We found that all ions adopt a side-on (η 2 ) mononuclear cobalt(III)-peroxo geometry in analogy with other structures reported in literature (Figure 2). [9][10][11][12][13] Moreover, this side-on O2 ligand adopts a distorted axial geometry which puts all the amino groups within the common natural hydrogen bonding distance (2.7 to 3.3 Å) of the axial oxygen atom (Table S2 in the Supporting Information). 14 Hydrogen bonding leads to a red shift of the N-H stretch to lower wavenumbers and the shift correlated with the bond strength of the hydrogen bonding.…”

Why intermolecular nitric oxide (NO) transfer? Exploring the factors and mechanistic aspects of NO transfer reaction

“…In addition to the above experimental results and their interpretations, labile & inert nature of more stable 6-CrNO (low spin d 5 , S = ½, inert) (Figure S15a) and less stable 5-Cr (high spin d 4 , S = 2, labile) (Figure S15b) suggests a huge change in the spin state which promotes the reaction to move in the forward direction. [37][38] The above discussion suggests that the ligand frameworks may influence the intermediate's stability and the rate of NO transfer; however, when it comes to the net transfer of coordinated NO moiety from one metal to another, it largely depends upon the stability of the metalcenter and various other physical parameters.…”

“…S15b †) suggests a huge change in the spin state, which promotes the reaction to move in the forward direction. 37,38 The above discussion suggests that the ligand frameworks may inuence the intermediate's stability and the rate of NO transfer; however, when it comes to the net transfer of coordinated NO moiety from one metal to another, it largely depends upon the stability of the metalcenter and various other physical parameters.…”