1
Tatsuya Higaki, Meng Zhou, Kelly J. Lambright, † Kristin Kirschbaum, † Matthew Y. Sfeir, ‡ and Rongchao Jin Sharp Transition from Nonmetallic Au 246 to Metallic Au 279 with Nascent Surface Plasmon Resonance Department of Chemistry, Carnegie Mellon University Introduction Transition Regime 0.1 nm 1 nm 10 nm 100 nm Plasmonic Nanoparticles Molecular Excitation (E g > 0) Atomically-Precise Nanoclusters Metallic Nonmetallic Au ~520 Au 333 Au 144 Au 133 …… 2.9 nm 2.3 nm 1.7 nm 1.6 nm …… ? Plasmonic Excitation (E g = 0) Au S How the Transition Occurs? Au 133 (S-Ph- t Bu) 52 Au 144 (S-CH 2 Ph) 60 Crystal Structures by SC-XRD Model Structures by TEM Atomically-Resolved Surface Pattern Objectives & Methods Unveil Critical Sizes and the Structures for the Transition! I. Atomically-Precise Synthesis of Au n with 200 < n < 300 II. Structure Determination of Au n by X-ray Crystallography III. Quantum State Determination of Au n by Spectroscopy (Collective Mode) Atomically-Precise Syntheses Crystal Structures “Size Focusing” [(C 8 H 17 ) 4 N][AuBr x Cl 4-x ] in Toluene Stirred at 80˚C w/ excess thiols NaBH 4 Au x (SR) y Au 246 (SR 1 ) 80 Au 279 (SR 2 ) 84 or or MALDI-MS + 1 2 Result I&II: Syntheses & Structures Decahedral Core in Au 246 Au 279 (SR) 8 4 Intensity (a.u.) m/z Au 246 Cuboctahedral Core in Au 279 Au S e.g., 1.8 1.6 1.4 1.2 1.0 0.8 e-ph Coupling Time (ps) 300 200 100 0 Pump Power (nJ/pulse) 5.0 4.8 4.6 4.4 4.2 4.0 Decay Time Constant (ps) 3. Higaki, T. et al. J. Am. Chem. Soc. 2018, 140, 5691. 7. Zhou, M.; Zeng, C.; Song, Y.; Padelford, J. W.; Wang, G.; Sfeir, M. Y.; Higaki, T.; Jin, R. Angew. Chem., Int. Ed. 2017, 56, 16257. 4. Zeng, C. et al. Science 2016, 354, 1580. Merely 33 Au-Atoms Difference Induced the Transition! h e Conclusion Q: Critical Sizes from Nonmetal to Metal Transition? A: Au 246 (SR) 80 and Au 279 (SR) 84 ! h e h e Metallic Nonmetallic E g E F Nanoparticles Diameter (nm) Au 246 Atoms Au 279 0.1 nm 1 nm 10 nm 100 nm Reference & Acknowledgement † Department of Chemistry and Biochemistry, University of Toledo ‡ Center for Functional Nanomaterials, Brookhaven National Laboratory Collaborators: Result III: Optical Properties Femtosecond Spectroscopy Femtosecond Laser Pulse 2. Probe 1. Pump Au 246 or Au 279 in Toluene Laser Power vs Time 900 700 500 300 Wavelength (nm) Abs. (a.u.) UV-Vis Spectra 600 506 400 Au 279 (SR) 84 Au 246 (SR) 80 460 Single Peak Multiple Peaks E (eV) Molecular Excitation a b c e.g., Au 25 (SR) 18 Plasmonic Excitation Multiple Peaks → Nonmetal e.g., Large Au NP 400 500 600 700 800 900 Wavelength (nm) Abs. (a.u.) Metal → Single Peak Slope > 0 → Metallic Slope ~ 0 → Non-Metallic Au 279 (SR) 84 Au 246 (SR) 80 1. Jin, R. et al. Chem. Rev. 2016, 116, 10346. 2. Hartland, G. V. Chem. Rev. 2011, 111, 3858. 5. Sakthivel, N. A. et al. J. Am. Chem. Soc. 2017, 139, 15450. 80 nm 50 nm 30 nm 20 nm 10 nm 3 nm 100 nm Diameter Au 279 (SR) 84 Au 246 (SR) 80 3. Analyze Relaxation Time fcc model Atomically-Defined Size & Structure! Au I S S “Staple” motif 6. Higaki, T. et al. Proc. Natl. Acad. Sci. U.S.A. 2019, 116, 13215.
![Receiver - Carnegie Mellon Universitynegi/publications/preprints/JSAC_camera.pdf · g1]i^ k)s t0iw i_romhpv'ko k)f h9pq)to r _s v s'k ktogbit0i3lnhpmpk kh _]3 qhqp roi` k)f h+u#t](https://static.dokumenty.site/doc/80x56/60ba3e242a7e97056506bd69/receiver-carnegie-mellon-university-negipublicationspreprintsjsac-g1i.jpg)
