Details

Autor(en) / Beteiligte

• Panda, Chakadola
• Chandra, Anirban
• Corona, Teresa
• Andris, Erik
• Pandey, Bhawana
• Garai, Somenath
• Lindenmaier, Nils
• Künstner, Silvio
• Farquhar, Erik R.
• Roithová, Jana
• Rajaraman, Gopalan
• Driess, Matthias
• Ray, Kallol

Titel

Nucleophilic versus Electrophilic Reactivity of Bioinspired Superoxido Nickel(II) Complexes

Ist Teil von

• Angewandte Chemie International Edition, 2018-11, Vol.57 (45), p.14883-14887

Auflage

International ed. in English

Ort / Verlag

Germany: Wiley Subscription Services, Inc

Erscheinungsjahr

2018

Quelle

Alma/SFX Local Collection

Beschreibungen/Notizen

• The formation and detailed spectroscopic characterization of the first biuret‐containing monoanionic superoxido‐NiII intermediate [LNiO2]− as the Li salt [2; L=MeN[C(=O)NAr)2; Ar=2,6‐iPr2C6H3)] is reported. It results from oxidation of the corresponding [Li(thf)3]2[LNiIIBr2] complex M with excess H2O2 in the presence of Et3N. The [LNiO2]− core of 2 shows an unprecedented nucleophilic reactivity in the oxidative deformylation of aldehydes, in stark contrast to the electrophilic character of the previously reported neutral Nacnac‐containing superoxido‐NiII complex 1, [L′NiO2] (L′=CH(CMeNAr)2). According to density‐functional theory (DFT) calculations, the remarkably different behaviour of 1 versus 2 can be attributed to their different charges and a two‐state reactivity, in which a doublet ground state and a nearby spin‐polarized doublet excited‐state both contribute in 1 but not in 2. The unexpected nucleophilicity of the superoxido‐NiII core of 2 suggests that such a reactivity may also play a role in catalytic cycles of Ni‐containing oxygenases and oxidases. It's Superoxo: A two‐state reactivity (TSR) rationalizes the contrasting reactivity patterns of two superoxido‐nickel(II) complexes involving the monoanionic β‐diketiminate and dianionic biuret ligands. This study underlines the importance of subtle electronic differences, which change the reactivity of biologically relevant O2‐M intermediates.