Iridium(I)/N-Heterocyclic Carbene Hybrid Materials: Surface Stabilization of Low-Valent Iridium Species for High Catalytic Hydrogenation Performance

Iuliia Romanenko (1) , David Gajan (2) , Reine Sayah (1) , Delphine Crozet (1) , Erwan Jeanneau (3) , Christine Lucas (1) , Lenaic Leroux (2) , Laurent Veyre (1) , Anne Lesage (2) , Lyndon Emsley (4, 2) , Emmanuel Lacote (1) , Chloé Thieuleux (1)

1 C2P2 - Laboratoire de Chimie, Catalyse, Polymères et Procédés, R 5265
2 Solid-State NMR Methods for Materials - Méthodes de RMN à l'état solide pour les matériaux
3 LMI - Laboratoire des Multimatériaux et Interfaces
4 EPFL - Ecole Polytechnique Fédérale de Lausanne

An Ir-I(NHC)-based hybrid material was prepared using a methodology which allowed the precise positioning and isolation of the Ir centers along the pore channels of a silica framework. The full characterization of the material by solid-state NMR spectroscopy showed that the supported Ir sites were stabilized by the silica surface, as low-coordinated single-site complexes. The material is extremely efficient for the hydrogenation of functional alkenes. The catalytic performance (TOF and TON) is one to two orders of magnitude higher than those of their molecular Ir analogues, and could be related to the prevention of the bimolecular deactivation of Ir complexes observed under homogeneous conditions.

Mots clés: DYNAMIC NUCLEAR-POLARIZATION; ENHANCED NMR-SPECTROSCOPY; MESOPOROUS SILICA; ENANTIOSELECTIVE HYDROGENATION; ASYMMETRIC HYDROGENATION; ALKENE METATHESIS; COMPLEXES; LIGANDS; REACTIVITY; ROUTE; carbenes; hydrogenation; iridium; solid-state structures; supported catalysts

Domaines: Chimie analytique

Iuliia Romanenko, David Gajan, Reine Sayah, Delphine Crozet, Erwan Jeanneau, et al.. Iridium(I)/N-Heterocyclic Carbene Hybrid Materials: Surface Stabilization of Low-Valent Iridium Species for High Catalytic Hydrogenation Performance. Angewandte Chemie International Edition, 2015, 53 (44), pp.12937-12941. ⟨10.1002/anie.201505867⟩. ⟨hal-01228564⟩