Rhodium and Iridium mediated oxygenations with oxygen: isolation of reactive metal intermediates


The project involves the isolation and characterization of highly reactive rhodium and iridium intermediates in new oxygenation reactions. Redoxactive diketimine ligands will open up new reaction pathways to access peroxido complexes, whereas dipyridylamino ligands will provide new reaction routes for oxygenations. O2 moieties can be bound at a transition metal centre as peroxido, superoxido ligand or even as formally neutral O2 ligand. The latter bounding mode will be explored at phosphine complexes. An additional activation of peroxide ligands will be accomplished on using Brønsted or Lewis acids such as Zn(OTf)2. On the basis of the stoichiometric studies new catalysts for oxygenation reactions will be developed.
The project involves the isolation and characterization of highly reactive rhodium and iridium intermediates in new oxygenation reactions. Redoxactive diketimine ligands will open up new reaction pathways to access peroxido complexes, whereas dipyridylamino ligands will provide new reaction routes for oxygenations. O2 moieties can be bound at a transition metal centre as peroxido, superoxido ligand or even as formally neutral O2 ligand. The latter bounding mode will be explored at phosphine complexes. An additional activation of peroxide ligands will be accomplished on using Brønsted or Lewis acids such as Zn(OTf)2. On the basis of the stoichiometric studies new catalysts for oxygenation reactions will be developed.


Principal Investigators
Braun, Thomas Prof. Dr. (Details) (Inorganic Chemistry)

Duration of Project
Start date: 09/2011
End date: 07/2015

Research Areas
Anorganische Chemie

Publications
G. Meier, T. Braun, Angew. Chem. 2011, 123, 3338-3342; Angew. Chem. Int. Ed. 2011, 50, 3280-3284.
"A Rhodium Peroxide Complex in Mono-, Di- and Peroxygenation Reactions"

A. Penner, T. Braun, Eur. J. Inorg. Chem. 2011, 2579-2587.
"Rhodium and Iridium Complexes with α-Diketimine Ligands: Oxidative Addition of H2 and O2"

G. Meier, T. Braun, Angew. Chem. 2012, 124, 12732-12737; Angew. Chem. Int. Ed. 2012, 51, 12564-12569.
"Hydrogenation of a Rhodium Peroxido Complex by Formate Derivatives: Mechanistic Studies and the Catalytic Formation of H2O2 from O2"

A. Eißler, P. Kläring, F. Emmerling, T. Braun, Eur. J. Inorg. Chem. 2013, 27, 4775-4788.
"α-Dialdimine Complexes of Rhodium(I) and Iridium(I): Their Reactivity with Dioxygen and Dihydrogen"

H. Baumgarth, T. Braun, B. Braun, R. Laubenstein, R. Herrmann, Eur. J. Inorg. Chem. 2015, 2015, 3157-3168.
"Synthesis of an iridium Peroxido Complex and its Reactivity Towards Brønsted Acids"

A. Bittner, T. Braun, R. Herrmann, S. Mebs, Chem. Eur. J. 2015, 21, 12299-12302.
"Rhodium-Mediated Oxygenation of Nitriles with Dioxygen: Isolation of Rhodium Derivatives of Peroxyimidic Acids"

Last updated on 2020-04-12 at 11:41