Ag44(EBT)26(TPP)4 Nanoclusters With Tailored Molecular and Electronic Structure. (9th March 2021)

• Record Type: Journal Article
• Authors: Bootharaju, Megalamane S.; Lee, Sanghwa; Deng, Guocheng; Malola, Sami; Baek, Woonhyuk; Häkkinen, Hannu; Zheng, Nanfeng; Hyeon, Taeghwan
• Is Part Of: Angewandte Chemie. Volume 133:Number 16(2021)
• Page Start: 9120
• Page End: 9126
• Publication Date: 2021-03-09
• Subjects: nanoclusters -- NIR-II photoluminescence -- silver -- single crystal X-ray structure -- superatoms; Chemistry -- Periodicals; 540
• DOI: 10.1002/ange.202015907
• Languages: English
• ISSNs: 0044-8249

Abstract

Abstract: Although atomically precise metalloid nanoclusters (NCs) of identical size with distinctly different molecular structures are highly desirable to understand the structural effects on the optical and photophysical properties, their synthesis remains highly challenging. Herein, we employed phosphine and thiol capping ligands featuring appropriate steric effects and synthesized a charge‐neutral Ag NC with the formula Ag44 (EBT)26 (TPP)4 (EBT: 2‐ethylbenzenethiolate; TPP: triphenylphosphine). The single‐crystal X‐ray structure reveals that this NC has a hollow metal core of Ag12 @Ag20 and a metal–ligand shell of Ag12 (EBT)26 (TPP)4 . The presence of mixed ligands and long V‐shaped metal–ligand motifs on this NC has resulted in an enhancement of the NIR‐II photoluminescence quantum yield by >25‐fold compared to an all‐thiolate‐stabilized anionic [Ag44 (SR)30 ] 4− NC (SR: thiolate). Time‐dependent density‐functional calculations show that our Ag44 NC is an 18‐electron superatom with a modulated electronic structure as compared to the [Ag44 (SR)30 ] 4− anion, significantly influencing its optical properties. Abstract : In this work, the synthesis and total structure determination of a novel Ag44 (EBT)26 (TPP)4 nanocluster, the first analogue of [Ag44 (SR)30 ] 4−, are reported. The identical size as well as similar core‐ and different surface‐structures of these two nanoclusters enable the study of the structural effect on the optical and photophysical properties. The novel surface structure plays a crucial role in the enhancement of NIR‐II photoluminescence.