Ag44 (EBT)26 (TPP)4 Nanoclusters With Tailored Molecular and Electronic Structure

Megalamane S Bootharaju; Sanghwa Lee; Guocheng Deng; Sami Malola; Woonhyuk Baek; Hannu Häkkinen; Nanfeng Zheng; Taeghwan Hyeon

doi:10.1002/anie.202015907

Ag₄₄ (EBT)₂₆ (TPP)₄ Nanoclusters With Tailored Molecular and Electronic Structure

Angew Chem Int Ed Engl. 2021 Apr 12;60(16):9038-9044. doi: 10.1002/anie.202015907. Epub 2021 Mar 9.

Authors

Megalamane S Bootharaju¹, Sanghwa Lee¹, Guocheng Deng², Sami Malola³, Woonhyuk Baek¹, Hannu Häkkinen³, Nanfeng Zheng², Taeghwan Hyeon¹

Affiliations

¹ Center for Nanoparticle Research, Institute for Basic Science (IBS), School of Chemical and Biological Engineering, Institute of Chemical Processes, Seoul National University, Seoul, 08826, Republic of Korea.
² State Key Laboratory for Physical Chemistry of Solid Surfaces, Collaborative Innovation Center of Chemistry for Energy Materials, Department of Chemistry, College of Chemistry and Chemical Engineering, Xiamen University, Xiamen, 361005, China.
³ Departments of Physics and Chemistry, Nanoscience Center, University of Jyväskylä, 40014, Jyväskylä, Finland.

PMID: 33372362
DOI: 10.1002/anie.202015907

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.

Keywords: NIR-II photoluminescence; nanoclusters; silver; single crystal X-ray structure; superatoms.

Abstract

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