title: Nitrenium ions as ligands for transition metals.
abstract: Unlike N-heterocyclic carbenes (NHCs), which are now used ubiquitously in metal-based chemistry, the nitrogen-derived analogue (in which a carbon is replaced with the isoelectronic nitrogen cation, a nitrenium ion) has remained elusive as a ligand for metals. This is especially intriguing, because several other main-group analogues of NHCs have been prepared, and have been shown to coordinate with transition-metal complexes. Here, we describe the preparation of several N-heterocyclic nitrenium ions that are isoelectronic and isostructural to NHCs, and study their ligand properties. The formation of relatively strong nitrenium-metal bonds is unambiguously confirmed, in solution by selective (15)N-labelling experiments, and in the solid state by X-ray crystallography. Experimental and computational studies of the electronic properties of this novel type of ligand suggest that they are poor σ-donors and good π-acceptors.
authors.affiliation: Schulich Faculty of Chemistry, Technion-Israel Institute of Technology, Technion City, Haifa 32000, Israel.
authors.forename: Yuri
authors.initials: Y
authors.lastname: Tulchinsky
authors.forename: Mark A
authors.initials: MA
authors.lastname: Iron
authors.forename: Mark
authors.initials: M
authors.lastname: Botoshansky
authors.forename: Mark
authors.initials: M
authors.lastname: Gandelman
mesh_terms: D018360:Crystallography, X-Ray; D006571:Heterocyclic Compounds; D007477:Ions; D008024:Ligands; D008697:Methane / Q000031:analogs & derivatives*; D008958:Models, Molecular; D015394:Molecular Structure; D009584:Nitrogen / Q000737:chemistry*; D009942:Organometallic Compounds / Q000737:chemistry*; D028561:Transition Elements / Q000737:chemistry*
chemical_list: D006571:Heterocyclic Compounds; D007477:Ions; D008024:Ligands; D009942:Organometallic Compounds; D028561:Transition Elements; C030011:carbene; D009584:Nitrogen; D008697:Methane