Journal article
Ultrafast Intersystem Crossing in Acetylacetone via Femtosecond X‑ray Transient Absorption at the Carbon K‑Edge
Journal of the American Chemical Society, Vol.139(46), pp.16576-16583
11/22/2017
DOI: 10.1021/jacs.7b07532
PMID: 29083165
Abstract
Molecular triplet states constitute a crucial gateway in the photochemical reactions of organic molecules by serving as a reservoir for the excess electronic energy. Here, we report the remarkable sensitivity of soft X-ray transient absorption spectroscopy for following the intricate electronic structure changes accompanying the non-adiabatic transition of an excited molecule from the singlet to the triplet manifold. Core-level X-ray spectroscopy at the carbon-1s K-edge (284 eV) is applied to identify the role of the triplet state (T1, 3ππ*) in the ultraviolet-induced photochemistry of pentane-2,4-dione (acetylacetone, AcAc). The excited-state dynamics initiated at 266 nm (1ππ*, S2) is investigated with element- and site-specificity using broadband soft X-ray pulses produced by high harmonic generation, in combination with time-dependent density functional theory calculations of the X-ray spectra for the excited electronic singlet and triplet states. The evolution of the core-to-valence resonances at the carbon K-edge establishes an ultrafast population of the T1 state (3ππ*) in AcAc via intersystem crossing on a 1.5 ± 0.2 ps time scale.
Details
- Title: Subtitle
- Ultrafast Intersystem Crossing in Acetylacetone via Femtosecond X‑ray Transient Absorption at the Carbon K‑Edge
- Creators
- Aditi Bhattacherjee - Lawrence Berkeley National LaboratoryChaitanya Das Pemmaraju - SLAC National Accelerator LaboratoryKirsten Schnorr - Lawrence Berkeley National LaboratoryAndrew R Attar - Lawrence Berkeley National LaboratoryStephen R Leone - University of California
- Resource Type
- Journal article
- Publication Details
- Journal of the American Chemical Society, Vol.139(46), pp.16576-16583
- DOI
- 10.1021/jacs.7b07532
- PMID
- 29083165
- NLM abbreviation
- J Am Chem Soc
- ISSN
- 0002-7863
- eISSN
- 1520-5126
- Publisher
- American Chemical Society
- Grant note
- DOI: 10.13039/100006151, name: Basic Energy Sciences, award: DE-AC02-05CH11231; DOI: 10.13039/100006235, name: Lawrence Berkeley National Laboratory; DOI: 10.13039/501100001663, name: Volkswagen Foundation
- Language
- English
- Date published
- 11/22/2017
- Academic Unit
- Chemistry
- Record Identifier
- 9984216689902771
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