Biological and Bioinspired Inorganic N–N Bond-Forming Reactions

Abstract

The metallobiochemistry underlying the formation of the inorganic N-N-bond-containing molecules nitrous oxide (N 2 O), dinitrogen (N 2 ), and hydrazine (N 2 H 4 ) is essential to the lifestyles of diverse organisms. Similar reactions hold promise as means to use N-based fuels as alternative, carbon-free energy sources. This review discusses research efforts to understand the mechanisms underlying biological N-N bond formation in primary metabolism and how the associated reactions are tied to energy transduction and organismal survival. These efforts comprise studies of both natural and engineered metalloenzymes, as well as synthetic model complexes.

Redox‐Neutral S‐nitrosation Mediated by a Dicopper Center

“…NO reductase, are well known. [50] Seminal work by Tolman and Karlin has shown that synthetic copper complexes can promote a similar NO • coupling reaction and generate N2O. We now demonstrate such a dicopper-promoted NO • process could be a potential strategy to facilitate the storage of NO • as S-nitrosothiol.…”

Activation of ammonia and hydrazine by electron rich Fe(ii) complexes supported by a dianionic pentadentate ligand platform through a common terminal Fe(iii) amido intermediate

“…It thus behaves as an Fe(II) aminyl 57 and is readily trapped by ArO• or scavenges H• atoms from appropriate donors (THF coordinated to Li, for example). Our attempts to generate it in the absence of such traps were motivated by the possibility that it might dimerize through N-N bond formation, which has been proposed in a variety of catalytic cycles, 68 and in particular for ammonia oxidation catalysts operating through the hydrazine pathway (Scheme 1). 9,10 Indeed, such a process has recently been observed in a related d 7 Ni(III) system.…”

Nitrogen isotope effects can be used to diagnose N transformations in wastewater anammox systems

“…In our experiments, variations in the 15 ε(NH 4 + ) values were observed in mainstream and enrichment experiments, where the anammox bacteria population is expected to be similar, which also argues against species dependence. Indeed, the Hzs enzyme seems well conserved across anammox clades 50 , and, therefore, the ammonium N isotope effect variation observed here cannot be attributed to sequence variations, and is more likely due to the changing experimental conditions (NH 4 + concentrations), as discussed above.…”