1. Interplay of kernel shape and surface structure for NIR luminescence in atomically precise gold nanorods.
- Author
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Wan XK, Han XS, Guan ZJ, Shi WQ, Li JJ, and Wang QM
- Abstract
It is challenging to attain strong near-infrared (NIR) emissive gold nanoclusters. Here we show a rod-shaped cluster with the composition of [Au
28 (p-MBT)14 (Hdppa)3 ](SO3 CF3 )2 (1 for short, Hdppa is N,N-bis(diphenylphosphino)amine, p-MBT is 4-methylbenzenethiolate) has been synthesized. Single crystal X-ray structural analysis reveals that it has a rod-like face-centered cubic (fcc) Au22 kernel built from two interpenetrating bicapped cuboctahedral Au15 units. 1 features NIR luminescence with an emission maximum at 920 nm, and the photoluminescence quantum yield (PLQY) is 12%, which is 30-fold of [Au21 (m-MBT)12 (Hdppa)2 ]SO3 CF3 (2, m-MBT is 3-methylbenzenethiolate) with a similar composition and 60-fold of Au30 S(S‑t‑Bu)18 with a similar structure. time-dependent DFT(TDDFT)calculations reveal that the luminescence of 1 is associated with the Au22 kernel. The small Stokes shift of 1 indicates that it has a very small excited state structural distortion, leading to high radiative decay rate (kr ) probability. The emission of cluster 1 is a mixture of phosphorescence and thermally activated delayed fluorescence(TADF), and the enhancement of the NIR emission is mainly due to the promotion of kr rather than the inhibition of knr . This work demonstrates that the metal kernel and the surface structure are both very important for cluster-based NIR luminescence materials., (© 2024. The Author(s).)- Published
- 2024
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