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

Si, Wei-Dan; Zhang, Chengkai; Zhou, Meng; Wang, Zhi; Feng, Lei; Tung, Chen-Ho; Sun, Di · Sci Adv · 2024

basic_science · Level V

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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 (<b>Au44a</b> and <b>Au44b</b>), by using tetraarylborates, capable of transferring aryl fragments to metal centers. X-ray crystallography reveals that both Au<sub>44</sub> nanoclusters contain an Au<sub>44</sub> 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<sub>44</sub> nanoclusters exhibit near-infrared (NIR) phosphorescence (λ<sub>max</sub> = 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.