Synthesis, Structure, and Spectroscopic Properties of Gold(I)−Carbene Complexes

Abstract

A series of gold(I)−carbene complexes of the type [Au(R2-bimy)L] (R = Et, Me; bimy = benzimidazol-2-ylidene; L = Cl, Br, I, bimy, thiophenolate, phenylacetylide) have been prepared. These carbene complexes are luminous in acetonitrile solution and in the solid state with long lifetimes at room temperature. Multiple emissions have been observed for different R and L. The crystal structure of [Au(Me2-bimy)Cl] shows a relatively short intermolecular AuI−AuI contact of 3.1664(10) Å and an intermolecular ring π−π interaction with a ring−ring distance of 3.45 Å. The structure of [Au(Et2-bimy)Cl], however, shows only intermolecular ring−ring interactions with a distance of 3.53 Å. Crystal structure data suggest that bimy is a high-trans-influence ligand.

Cyclic (alkyl)(amino)carbene gold(I) complexes: A synthetic and structural investigation

“…Here again, the 13 C NMR signal for the carbene carbon of 2d appeared at lower field (251.2 ppm) than that observed for 1d (235.0 ppm). (Table 1), and are in agreement with the literature for gold(I) complexes [12,[20][21][22][23][24][25][26][27][28][29][30][31]. The Au-C carbene bond lengths in 1a (1.987(9) Å) and 1b (1.983(2) Å) are comparable with those found in substituted NHC gold(I) chloro complexes [12,[18][19][20][21][22][23], and suggest a single bond character, in good agreement with the strong σ-donor character of CAACs.…”

“…(Table 1), and are in agreement with the literature for gold(I) complexes [12,[20][21][22][23][24][25][26][27][28][29][30][31]. The Au-C carbene bond lengths in 1a (1.987(9) Å) and 1b (1.983(2) Å) are comparable with those found in substituted NHC gold(I) chloro complexes [12,[18][19][20][21][22][23], and suggest a single bond character, in good agreement with the strong σ-donor character of CAACs. The cationic complexes 2d and 2e have slightly longer Au-C carbene bond lengths [2.0321(11) and 2.033(4) Å, respectively] in the range observed for cationic dicarbene (NHC) gold(I) complexes [24][25][26][27][28][29][30][31].…”

Allene formation by gold catalyzed cross-coupling of masked carbenes and vinylidenes

“…LAu( 2 -alkyne) ϩ X Ϫ complexes such as 9a have been proposed as reactive intermediates in numerous catalytic cycles, but only a single isolable example has been reported (36). The yellow solution, resulting from subsequent addition of enamine 4a to a solution of 9a, was identified by 13 C and 1 H NMR spectroscopy as a 1:1 mixture of the neutral complex 10a (37) and salt 11a (Fig. 5); an independent preparation of 10a and 11a confirmed their identity.…”

Synthesis and Characterization of Gold(I) and Gold(III) Complexes Derived from Benzimidazolin‐2‐ylidene Ligands

“…The inertness of the Au-C NHC bond during substitution reactions at linear [AuX(NHC)] complexes was noted by Wang and Lin as early as 1999 [16]. Ligand X in complexes of the type [AuX(NHC)] can be substituted for halides [16,17], nitrogen- [18,19] and phosphorus-donors [4a, 19] or even hydroxide [20].…”