Donor Strength Determination of Anionic Ligands.

14 new gold(I) NHC complexes of the type [AuX( i Pr 2 -bimy)] ( i Pr 2 -bimy = 1,3-diisopropylbenzimidazolin-2-ylidene) have been prepared and fully characterized. These complexes and their reported analogues were used to systematically compare and rank the donating abilities of overall 34 anionic X-type donors by 13 C NMR spectroscopy. Specifically, the carbene chemical shift of the i Pr 2 -bimy ligand was found to be responsive to the ligand X spanning an overall range Δδ > 37 ppm between the strongest and weakest donor in this study.