A Serendipitous Rendezvous with a Four‐Center Two‐Electron Bonded Intermediate in the Aerial Oxidation of Hydrazine. Issue 4 (22nd December 2015)

• Record Type: Journal Article
• Authors: Banerjee, Ambar; Ganguly, Gaurab; Roy, Lisa; Pathak, Shubhrodeep; Paul, Ankan
• Is Part Of: Chemistry. Volume 22:Issue 4(2016)
• Page Start: 1216
• Page End: 1222
• Publication Date: 2015-12-22
• Subjects: aromaticity -- dioxygen activation -- molecular dynamics -- multicenter bonding -- spin–orbit coupling; Chemistry -- Periodicals; 540
• DOI: 10.1002/chem.201503455
• Languages: English
• ISSNs: 0947-6539

Abstract

Abstract: Oxidation by dioxygen has a rich repertoire of mechanistic intricacies. Herein, we report a hitherto unknown paradigm of dioxygen activation reaction which propagates through a four center two electron (4c–2e) bound species. Using static DFT and ab initio quantum chemical techniques we have unraveled the oxidation pathway for hydrazine and its methylated analogues by dioxygen which involves formation of this unconventional 4c–2e bonded species en route to the oxidation products. Inconvertible evidence in favor of such an unprecedented dioxygen activation route is provided by capturing the events of formation of the 4c–2e species in aqueous phase for hydrazine and its congeners and the experimentally observed products from the respective 4c–2e species, like H2 O2 and N2 H2, diazene in the case of hydrazine using Car–Parrinello molecular dynamics simulations. Abstract : Oxidative hitchhike through aromaticity : Static and dynamic theoretical studies reveal that hydrazine oxidation by dioxygen proceeds through an intermediate which shows 4c–2e bonding marked by exceptionally long N−O bonds and significant aromatic character. This is the first example in which a 4c–2e species is found in a reaction involving naturally existing molecules (see figure).