INOR 122 |
| Diaminocarbenes are among the most potent σ-donor ligands available for binding to transition metals. We have investigated the nucleophilic addition of amines to metal-bound isocyanides as a versatile synthetic route to new diaminocarbene complexes of late transition metals for use in catalysis and other applications. Judicious electronic tuning of the isocyanide substituents has been found to promote self-assembly of a variety of chelated bis(carbene) late metal complexes from structurally diverse diamine precursors, including chiral examples. The stabilities of the resulting complexes as a function of chelate ring size have been investigated. For example, a chelated bis(carbene) palladium complex with a 5-membered chelate ring exhibits reversible ring opening to form a monocarbene-isocyanide complex, and a van't Hoff analysis of this equilibrium allowed interrogation of the metal-carbene bond energetics. Larger chelate rings showed greatly enhanced stability and suitability for catalysis. Evaluations of the σ-donor abilities of the carbene ligands will be reported. |
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Organometallic: Synthesis
1:30 PM-4:50 PM, Sunday, 10 September 2006 Moscone Center -- Room 310, Oral
Division of Inorganic Chemistry |