N-Heterocyclic carbene-based C-centered Au(I)-Ag(I) clusters with intense phosphorescence and organelle-selective translocation in cells

Abstract

Photoluminescent gold clusters are functionally variable chemical modules by ligand design. Chemical modification of protective ligands and introduction of different metals into the gold clusters lead to discover unique chemical and physical properties based on their significantly perturbed electronic structures. Here we report the synthesis of carbon-centered Au(I)-Ag(I) clusters with high phosphorescence quantum yields using N-heterocyclic carbene ligands. Specifically, a heterometallic cluster [(C)(AuI-L)6AgI2]4+, where L denotes benzimidazolylidene-based carbene ligands featuring N-pyridyl substituents, shows a significantly high phosphorescence quantum yield (Φ = 0.88). Theoretical calculations suggest that the carbene ligands accelerate the radiative decay by affecting the spin-orbit coupling, and the benzimidazolylidene ligands further suppress the non-radiative pathway. Furthermore, these clusters with carbene ligands are taken up into cells, emit phosphorescence and translocate to a particular organelle. Such well-defined, highly phosphorescent C-centered Au(I)-Ag(I) clusters will enable ligand-specific, organelle-selective phosphorescence imaging and dynamic analysis of molecular distribution and translocation pathways in cells.

Recent progress in dichalcophosphate coinage metal clusters and superatoms

“…14 An almost unlimited set of C-, P-, S-, Se-and Te-donating ligands, as well as their ability to modulate the structure of clusters and tune their properties, open up wide prospects for the design of the most fascinating cluster complexes. Up to now, a plethora of Cu, Ag and Au clusters supported by chalcogenide, [15][16][17][18] phosphine, 19,20 carbene, 21 alkynyl, 22,23 and polyoxometalate 24 anions were assembled. Other remarkable families of supporting ligands for stable group 11 metal clusters are dichalcophosphates ([(RO) 2 PE 2 ] À ) (E = S or Se), 25,26 which are readily available on a large scale from the cheapest starting reagents -P 2 S 5 or P 2 Se 5 and diverse alcohols.…”

Photoluminescence control by atomically precise surface metallization of C-centered hexagold(i) clusters using N-heterocyclic carbenes

“…43,44 In our recent work, we found that NHC ligands may further enhance the emission of heterometallic clusters. 32 These results suggest that, the silver(I) adatoms and NHC ligands synergistically contribute to the photoluminescence properties of heterometallic clusters.…”

“…§ CAu I 6 Ag I 2 -type cluster 2 was synthesized according to our previously reported literature. 32 Next, heterometallic clusters were synthesized from clusters 5 and 6. The CAu (Fig.…”

“…30 More surprisingly, the heterometallic [(C)(Au I -BIPy) 6 Ag I 2 ](BF 4 ) 4 (2, BIPy = N-isopropyl-N ′ -2-pyridylbenzimidazolylidene) shows blue-shied emission and 3 times higher QY in solution than [(C)(Au I -dppy) 6 Ag I 2 ](BF 4 ) 4 (dppy = 2-pyridyldiphenylphosphine). 32,37 Previously, Wang and co-workers reported a series of carboncentered, phosphine-protected Au I -Ag I clusters. [37][38][39][40][41][42][43][44] The second layer of Ag I ions on the cluster surface fully protects the core portion, resulting in long life and highly efficient emission.…”

Zn2+-Induced Gold Cluster Aggregation Enhanced Electrochemiluminescence for Ultrasensitive Detection of MicroRNA-21

“…Compared with other analytical technologies such as colorimetric method and photoluminescence with low sensitivity, high background, and complex operation, ECL technology is characterized by high sensitivity, low background, simple equipment, and favorable controllability, which has attracted much attention in the field of clinical diagnosis, environmental analysis, and food safety . Currently, gold nanoclusters (Au NCs) with excellent biocompatibility, unique catalysis, and outstanding optical and electrochemical properties , have drawn tremendous attention as ECL emitters. − However, Au NCs have been confronted with low ECL efficiency, which limited its ECL applications. Recently, in order to improve the ECL efficiency of Au NCs, monodispersed Au NCs were assembled by various means (such as host and guest recognition, gel network formation, and metal–organic framework insertion) to explore the aggregation-induced emission (AIE) effect of Au NCs.…”