Superatom State-Resolved Dynamics of the Au25(SC8H9)18(-) Cluster from Two-Dimensional Electronic Spectroscopy
| Autor: | Kenneth L. Knappenberger, Giulio Cerullo, Aurelio Oriana, Luca Sala, Julien Réhault, Tatjana Stoll, Enrico Sgro, Jeremy W. Jarrett, Federico Branchi |
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| Rok vydání: | 2016 |
| Předmět: |
Chemistry
Superatom Relaxation (NMR) Chemistry (all) 02 engineering and technology General Chemistry Photon energy 010402 general chemistry 021001 nanoscience & nanotechnology 01 natural sciences Electron spectroscopy Catalysis Biochemistry Colloid and Surface Chemistry 0104 chemical sciences Femtosecond Molecular orbital Atomic physics 0210 nano-technology Ground state Excitation |
| Zdroj: | Journal of the American Chemical Society. 138(6) |
| ISSN: | 1520-5126 |
| Popis: | Superatom state-resolved dynamics of the Au25(SC8H9)18(-) monolayer-protected cluster (MPC) were examined using femtosecond two-dimensional electronic spectroscopy (2DES). The electronic ground state of the Au25(SC8H9)18(-) MPC is described by an eight-electron P-like superatom orbital. Hot electron relaxation (200 ± 15 fs) within the superatom D manifold of lowest-unoccupied molecular orbitals was resolved from hot hole relaxation (290 ± 20 fs) in the superatom P states by using 2DES in a partially collinear pump-probe geometry. Electronic relaxation dynamics mediated by specific superatom states were distinguished by examining the time-dependent cross-peak amplitudes for specific excitation and detection photon energy combinations. Quantification of the time-dependent amplitudes and energy positions of cross peaks in the 2.21/1.85 eV (excitation/detection) region confirmed that an apparent energetic blue shift observed for transient bleach signals results from rapid hot electron relaxation in the superatom D states. The combination of structurally precise MPCs and state-resolved 2DES can be used to examine directly the influence of nanoscale structural modifications on electronic carrier dynamics, which are critical for developing nanocluster-based photonic devices. |
| Databáze: | OpenAIRE |
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