Low-valent homobimetallic Rh complexes: influence of ligands on the structure and the intramolecular reactivity of Rh-H intermediates

Pascal Jurt (1) , Oleg G. Salnikov (2, 3) , Thomas L. Gianetti (4) , Nikita V. Chukanov (2, 3) , Matthew G. Baker (1) , Gregoire Le Corre (1) , Jaap E. Borger (1) , Rene Verel (1) , Sebastien Gauthier (5) , Olaf Fuhr (6) , Kirill V. Kovtunov (2, 3) , Alexey Fedorov (1) , Dieter Fenske (6) , Igor V. Koptyug (2) , Hansjorg Grutzmacher (1)

1 ETH Zürich - Eidgenössische Technische Hochschule - Swiss Federal Institute of Technology [Zürich]
2 RAS - Russian Academy of Sciences [Moscow]
3 NSU - Novosibirsk State University
4 University of Arizona
5 ISCR - Institut des Sciences Chimiques de Rennes
6 KIT - Karlsruhe Institute of Technology

Supporting two metal binding sites by a tailored polydentate trop-based (trop = 5H-dibenzo[a,d]cyclohepten-5-yl) ligand yields highly unsymmetric homobimetallic rhodium(i) complexes. Their reaction with hydrogen rapidly forms Rh hydrides that undergo an intramolecular semihydrogenation of two C and xe002;C bonds of the trop ligand. This reaction is chemoselective and converts C and xe002;C bonds to a bridging carbene and an olefinic ligand in the first and the second semihydrogenation steps, respectively. Stabilization by a bridging diphosphine ligand allows characterization of a Rh hydride species by advanced NMR techniques and may provide insight into possible elementary steps of H-2 activation by interfacial sites of heterogeneous Rh/C catalysts.

Domains: Chemical Sciences; Coordination chemistry

Pascal Jurt, Oleg G. Salnikov, Thomas L. Gianetti, Nikita V. Chukanov, Matthew G. Baker, et al.. Low-valent homobimetallic Rh complexes: influence of ligands on the structure and the intramolecular reactivity of Rh-H intermediates. Chemical Science, 2019, 10 (34), pp.7937-7945. ⟨10.1039/c9sc02683e⟩. ⟨hal-02303398⟩