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The Synthesis of [Sn10SiSiMe334]2- Using a Metastable SnI Halide Solution Synthesized via a Co-condensation Technique
Published on: November 28, 2016
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Increased Excited State Metallicity in Neutral Cr2O Clusters (n < 5) upon Sequential Oxidation
Jacob M Garcia1,2, Scott G Sayres1,2
1School of Molecular Sciences, Arizona State University, Tempe, Arizona 85287, United States.
Journal of the American Chemical Society
|September 13, 2021
Summary
The study measured excited state lifetimes of chromium oxide clusters using femtosecond spectroscopy. Increasing oxidation gradually shifts clusters from semiconducting to metallic behavior, enabling molecular spintronics design.
Area of Science:
- Physical Chemistry
- Materials Science
- Surface Science
Background:
- Understanding excited state dynamics is crucial for designing new materials.
- Chromium oxide clusters exhibit complex electronic structures influenced by oxidation state.
Purpose of the Study:
- To investigate the excited state lifetimes and relaxation pathways of neutral chromium oxide (Cr2O) clusters.
- To correlate electronic structure changes with oxidation state using computational methods.
- To explore potential applications in molecular spintronics.
Main Methods:
- Femtosecond pump-probe spectroscopy was employed to measure excited state lifetimes.
- Density functional theory (DFT) calculations were performed to analyze electronic structure.
- Analysis of charge transfer character and relaxation processes was conducted.
Main Results:
- Three distinct relaxation processes were observed upon UV photon absorption.
- Subpicosecond lifetimes were attributed to vibrational relaxation in all clusters.
- A ∼30 fs transient signal correlated with oxidation and charge transfer, indicating a semiconducting-to-metallic transition.
- A long-lived (>2.5 ps) response in oxidized clusters suggests efficient adiabatic relaxation.
Conclusions:
- Excited state dynamics of Cr2O clusters are strongly dependent on oxidation.
- A gradual transition from semiconducting to metallic behavior is observed at the molecular level.
- These findings open avenues for designing novel molecular spintronic materials.
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