Author: ["Holger Braunschweig","Alexander Damme","Rian D. Dewhurst","Alfredo Vargas"]
CITE.CC academic search helps you expand the influence of your papers.
Abstract
Transition-metal catalysis is founded on the principle that electron donation from a metal to a ligand is accepted by an antibonding orbital of the ligand, thereby weakening one of the bonds in the ligand. Without this, the initial step of bond activation in many catalytic processes would simply not occur. This concept is enshrined in the well-accepted Dewar–Chatt–Duncanson model of transition-metal bonding. We present herein experimental and computational evidence for the first true violation of the Dewar–Chatt–Duncanson bonding model, found in a π-diborene complex in which an electron-rich group 10 metal donates electrons into an empty bonding π orbital on the ligand, and thereby strengthens the bond. The complex is also the first transition-metal complex to contain a bound diborene, a species not isolated before, either in its free form or bound to a metal. A form of π backbonding is observed in a π-diborene complex of platinum, and confirmed by calculations. This interaction partially fills a bonding π orbital on the diborene ligand, strengthening the B–B bond. That π backbonding can strengthen bonds overturns ingrained notions that π backbonding is exclusively a bond-weakening phenomenon. Cite this article
Braunschweig, H., Damme, A., Dewhurst, R. et al. Bond-strengthening π backdonation in a transition-metal π-diborene complex. Nature Chem 5, 115–121 (2013). https://doi.org/10.1038/nchem.1520 