5-acetyl-imidazol-2-ylidene-4-olate ligand (IMes-acac): Synthesis, coordination chemistry and evaluation of the electronic communication

Sadie F. DePeter,^a Valentina Mallardo,^a Adela Nano,^b Georges Dahm,^b Noël Lugan,^a Stéphane Bellemin-Laponnaz,^b Vincent César^a

a Laboratoire de Chimie de Coordination du CNRS (UPR 8241), 205 route de Narbonne, 31077 Toulouse Cedex 04, France
b Institut de Physique et Chimie des Matériaux de Strasbourg, CNRS UMR 7504, Université de Strasbourg, 23 rue du Loess BP43, 67034 Strasbourg Cedex 2, France

N-Heterocyclic Carbenes (NHCs) have emerged as outstanding ligands in organometallic chemistry.[1] In recent years, NHCs have branched out from their original applications in homogeneous catalysis to implementation in fields such as luminescent materials, metallopharmaceuticals, and other functional materials. Hybrid, ambidentate NHCs combine the benefits of the strongly coordinating properties of NHCs with a specific functionality brought by another common coordinating unit. The design of these complexes is a promising strategy to expand the application scope of NHCs. In this poster, we will present the results of our study on the 5-acetylimidazol-2-ylidene-4-olate or (IMes-acac)^- ligand, composed of a strongly-coordinating diaminocarbene unit fused with an acetylacetonate (acac) moiety.[2] We have synthesized bimetallic and trimetallic complexes bridged by this ligand and investigated its possible allowance of electronic communication between coordinated metal centers.

[1] Hopkinson, M. N.; Richter, C.; Schedler, M.; Glorius, F., Nature 2014, 510, 485.

[2] This ligand was disclosed in a first communication last year: César, V.; Mallardo, V.; Nano, A.; Dahm, G.; Lugan, N.; Lavigne, G.; Bellemin-Laponnaz, S., Chem. Commun. 2015, 51, 5271.