Ring Nitrogenation of Aromatic Amines by the Excited State of an Osmium(VI) Nitrido Complex.
Inorg Chem
; 62(4): 1447-1454, 2023 Jan 30.
Article
em En
| MEDLINE
| ID: mdl-36633522
ABSTRACT
The reactivity of electrophilic OsVI and RuVI nitrides toward various aliphatic and aromatic amines have been previously reported; these reactions all go through an initial nucleophilic addition of the amine nitrogen to MVI≡N (M = Os, Ru) to generate a MIV hydrazido species. Herein, we report that the excited state of a luminescent osmium(VI) nitrido complex, [OsVI(N)(L)(CN)3]- (OsN, HL = 2-(2-hydroxy-5-nitrophenyl)benzoxazole), undergoes unprecedented ring nitrogenation of aromatic amines. Visible-light irradiation of OsN generates OsN*, which predominantly attacks the aromatic ring of 2,6-dimethylaniline (Me2PhNH2) to give an Os(II) benzoquinone diimine compound (PPh4)[OsII(L)(CN)3(p-NHâMe2PhâNH2)] [(PPh4)2] in 60% yield, while nucleophilic addition of the amine N to OsN* also occurs to give the osmium(II) diazonium compound (PPh4)[OsII(L)(CN)3(N = N-Me2Ph)] [(PPh4)1] as a minor product (10% yield). On the other hand, OsN* undergoes exclusive ring nitrogenation of diphenylamine, indole, and carbazole to give the corresponding osmium(II) benzoquinone diimines. All products have been characterized by various spectroscopic techniques and by X-ray crystallography. The reaction between OsN* and Ar2N is proposed to proceed via an initial 1e- transfer (ET) followed by proton transfer (PT) to generate OsVNH and Ar2N⢠intermediates, which then further combine to give the product. The benzoquinone diimine ligands are susceptible to oxidation. Oxidation of 2 with H2O2 at ambient conditions affords [OsIV(L)(CN)3(NâPhMe2(O)âO)]-, which bears the previously unknown (epoxy)benzoquinone iminato ligand.
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Bases de dados:
MEDLINE
Idioma:
En
Revista:
Inorg Chem
Ano de publicação:
2023
Tipo de documento:
Article
País de afiliação:
China