A series of N-heterocyclic carbene-based Au I-Ï-acetylide complexes of the type [(Bimz)Au-C⋯CR] (Bimz = benzimidazolin-2-ylidene; R = aryl, silyl groups) (1a-1l, 2, 3) were prepared from the precursor [(Bimz)Au ICl] by an in situ deprotonation of the terminal alkynes. Steady-state photoluminescence studies revealed that most of these complexes exhibit phosphorescence at room temperature and in 77 K rigidified matrices. Molecular structures were determined by single-crystal X-ray diffraction studies for complexes 1a, 1b, 1e, 1f, 1h, 1k, and 1l. Complexes 1f, 1h, and 1l revealed weak unsupported aurophilic interactions. Cyclic voltammetry studies exhibited irreversible behavior with one oxidation peak potential (E p,a) for most cases in the region 0.7-1.4 V. Experimental and DFT studies suggest that the nature of the emission is predominantly of intraligand character 3IL(π-π*) with a slight perturbation from the metal.
- N-Heterocyclic carbenes