Arylgold nanoclusters: Phenyl-stabilized Au 44 with thermal-controlled NIR single/dual-channel phosphorescence

Abstract

Arylation of gold holds paramount importance in the domain of organometallic chemistry; however, the exploration of arylgold nanoclusters remains in its infancy primarily due to the synthetic challenge. Here, we present a facile and effective arylation strategy to directly synthesize two arylgold nanoclusters ( Au44a and Au44b ), by using tetraarylborates, capable of transferring aryl fragments to metal centers. X-ray crystallography reveals that both Au 44 nanoclusters contain an Au 44 kernel co-protected by six aryl groups, two tetrahydrothiophene, and 16 alkynyl-ether ligands, the latter is generated in situ through Williamson ether reaction during the assembly processes. Notably, Au 44 nanoclusters exhibit near-infrared (NIR) phosphorescence (λ max = 958 nm) and microsecond radiative relaxation at ambient condition, which is a thermal-controlled single/dual-channel phosphorescent emission revealed by temperature-dependent NIR, time-resolved emission, and femtosecond/nanosecond transition absorption spectra. This work represents a breakthrough in using aryl as protective ligands for the construction of gold nanoclusters, which is poised to have a transformative impact on organometallic nanoclusters.