Plasmonic Nanomolecules: Electrochemical Resolution of 22 Electronic States in Au<sub>329</sub>(SR)<sub>84</sub>

Dass, Amala; Sakthivel, Naga Arjun; Jupally, Vijay Reddy; Kumara, Chanaka; Rambukwella, Milan

doi:10.1021/acsenergylett.9b02528

Cited by 22 publications

(28 citation statements)

References 75 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The ease of operation coupled with the control over the separation of closely related sizes makes SEC a powerful indispensable tool to isolate monodisperse nanomolecules in a preparative scale. Our group has used these setups for almost a decade and published reports on numerous AuNMs and their properties and applications (we refer the reader to some of our reports using SEC ,,− ).…”

Section: Introductionmentioning

confidence: 99%

Size Exclusion Chromatography: An Indispensable Tool for the Isolation of Monodisperse Gold Nanomolecules

et al. 2021

Self Cite

View full text Add to dashboard Cite

Highly monodisperse and pure samples of atomically precise gold nanomolecules (AuNMs) are essential to understand their properties and to develop applications using them. Unfortunately, the synthetic protocols that yield a single-sized nanomolecule in a single-step reaction are unavailable. Instead, we observe a polydisperse product with a mixture of core sizes. This product requires post-synthetic reactions and separation techniques to isolate pure nanomolecules. Solvent fractionation based on the varying solubility of different sizes serves well to a certain extent in isolating pure compounds. It becomes tedious and offers less control while separating AuNMs that are very similar in size. Here, we report the versatile and the indispensable nature of using size exclusion chromatography (SEC) as a tool for separating nanomolecules and nanoparticles. We have demonstrated the following: (1) the ease of separation offered by SEC over solvent fractionation; (2) the separation of a wider size range (∼5–200 kDa or ∼1–3 nm) and larger-scale separation (20–100 mg per load); (3) the separation of closely sized AuNMs, demonstrated by purifying Au137(SR)56 from a mixture of Au329(SR)84, Au144(SR)60, Au137(SR)56, and Au130(SR)50, which could not be achieved using solvent fractionation; (4) the separation of AuNMs protected by different thiolate ligands (aliphatic, aromatic, and bulky); and (5) the separation can be improved by increasing the column length. Mass spectrometry was used for analyzing the SEC fractions.

show abstract

Section: Introductionmentioning

confidence: 99%

Size Exclusion Chromatography: An Indispensable Tool for the Isolation of Monodisperse Gold Nanomolecules

et al. 2021

Self Cite

View full text Add to dashboard Cite

show abstract

“…Currently, discrepancies in the literature dispute such a trend of monotonous dependence in the nonmetal to metal transition range. Au 246 (p-MBT) 80 is shown to be the largest nonmetallic nanocluster in the quantum size regime to date, whereas Au 329 (PET) 84 is found to have no obvious electrochemical gap and being metallic. − Furthermore, Au 279 (TBBT) 84 is determined to be metallic by transient absorption spectroscopy but electrochemistry analysis is still absent. , An abnormal case is the electrochemical properties of Au 133 (TBBT) 52 reported by Dass and co-workers, in which no electrochemical energy gap in Au 133 was identified . The same report analyzed Au 144 (PET) 60 and showed a clear ∼0.37 V peak spacing. , Theoretical analyses on Au 144 and similar-sized Au 146 also showed small gaps. , Further, the similar-sized Au 130 exhibits a clear ∼0.45 and 0.50 V voltammetric peak spacing with monothiol ligands , and ∼0.35 V with mixed mono- and di-thiol ligands in earlier work .…”

mentioning

confidence: 99%

Inhomogeneous Quantized Single-Electron Charging and Electrochemical–Optical Insights on Transition-Sized Atomically Precise Gold Nanoclusters

Chen

Higaki

et al. 2020

ACS Nano

View full text Add to dashboard Cite

Small differences in electronic structures, such as an emerging energy band gaps or the splitting of degenerated orbitals, are very challenging to resolve but important for nanomaterials properties. A signature electrochemical property called quantized double layer charging, i.e., "continuous" oneelectron transfers (1e, ETs), in atomically precise Au 133 (TBBT) 52 , Au 144 (BM) 60 , and Au 279 (TBBT) 84 is analyzed to reveal the nonmetallic to metallic transitions (whereas TBBT is 4-tert-butylbenzenethiol and BM is benzyl mercaptan; abbreviated as Au 133 , Au 144 , and Au 279 ). Subhundred milli-eV energy differences are resolved among the "often-approximated uniform" peak spacings from multipairs of reversible redox peaks in voltammetric analysis, with single ETs as internal standards for calibration and under temperature variations. Cyclic and differential pulse voltammetry experiments reveal a 0.15 eV energy gap for Au 133 and a 0.17 eV gap for Au 144 at 298 K. Au 279 is confirmed metallic, displaying a "bulk-continuum" charging response without an energy gap. The energy gaps and double layer capacitances of Au 133 and Au 144 increase as the temperature decreases. The temperature dependences of charging energies and HOMO−LUMO gaps of Au 133 and Au 144 are attributed to the counterion permeation and the steric hindrance of ligand, as well as their molecular compositions. With the subtle energy differences resolved, spectroelectrochemistry features of Au 133 and Au 144 are compared with ultrafast spectroscopy to demonstrate a generalizable analysis approach to correlate steady-state and transient energy diagram for the energy-in processes. Electrochemiluminescence (ECL), one of the energyout processes after the charge transfer reactions, is reported for the three samples. The ECL intensity of Au 279 is negligible, whereas the ECLs of Au 133 and Au 144 are relatively stronger and observable (but orders of magnitudes weaker than our recently reported bimetallic Au 12 Ag 13 ). Results from these atomically precise nanoclusters also demonstrate that the combined voltammetric and spectroscopic analyses, together with temperature variations, are powerful tools to reveal subtle differences and gain insights otherwise inaccessible in other nanomaterials.

show abstract

“…The DPV curve of Ag 100 in Figure d features six oxidation states, including three oxidation peaks at 0.28 (O 1 ), 0.53 (O 2 ), 1.05 V (O 3 ), and three reduction peaks at 0.04 (R 1 ), −0.16 (R 2 ), and −0.36 V (R 3 ). R 3 to O 2 show typical quantized double‐layer (QDL) charging behavior, without a discernible electrocchemical gap. The average potential spacing between R 3 to O 2 is about 0.2 eV.…”

Section: Figurementioning

confidence: 99%

Rhombicuboctahedral Ag₁₀₀: Four‐Layered Octahedral Silver Nanocluster Adopting the Russian Nesting Doll Model

Bai

Song

et al. 2020

Angewandte Chemie

View full text Add to dashboard Cite

Precise atomic structure of metal nanoclusters (NCs) is fundamental for elucidating the structure–property relationships and the inherent size‐evolution principles. Reported here is the largest known FCC‐based (FCC=face centered cubic) silver nanocluster, [Ag100(SC6H33,4F2)48(PPh3)8]−: the first all‐octahedral symmetric nesting Ag nanocluster with a four‐layered Ag6@Ag38@Ag48S24@Ag8S24P8 structure, consistent symmetry elements, and a unique rhombicuboctahedral morphology distinct from theoretical predictions and previously reported FCC‐based Ag clusters. DFT studies revealed extensive interlayer interactions and degenerate frontier orbitals. The FCC‐based Russian nesting doll model constitutes a new platform for the study of the size‐evolution principles of Ag NCs.

show abstract

Plasmonic Nanomolecules: Electrochemical Resolution of 22 Electronic States in Au₃₂₉(SR)₈₄

Cited by 22 publications

References 75 publications

Size Exclusion Chromatography: An Indispensable Tool for the Isolation of Monodisperse Gold Nanomolecules

Size Exclusion Chromatography: An Indispensable Tool for the Isolation of Monodisperse Gold Nanomolecules

Inhomogeneous Quantized Single-Electron Charging and Electrochemical–Optical Insights on Transition-Sized Atomically Precise Gold Nanoclusters

Rhombicuboctahedral Ag₁₀₀: Four‐Layered Octahedral Silver Nanocluster Adopting the Russian Nesting Doll Model

Contact Info

Product

Resources

About

Plasmonic Nanomolecules: Electrochemical Resolution of 22 Electronic States in Au329(SR)84

Cited by 22 publications

References 75 publications

Size Exclusion Chromatography: An Indispensable Tool for the Isolation of Monodisperse Gold Nanomolecules

Size Exclusion Chromatography: An Indispensable Tool for the Isolation of Monodisperse Gold Nanomolecules

Inhomogeneous Quantized Single-Electron Charging and Electrochemical–Optical Insights on Transition-Sized Atomically Precise Gold Nanoclusters

Rhombicuboctahedral Ag100: Four‐Layered Octahedral Silver Nanocluster Adopting the Russian Nesting Doll Model

Contact Info

Product

Resources

About

Plasmonic Nanomolecules: Electrochemical Resolution of 22 Electronic States in Au₃₂₉(SR)₈₄

Rhombicuboctahedral Ag₁₀₀: Four‐Layered Octahedral Silver Nanocluster Adopting the Russian Nesting Doll Model