A5063307488- Spectroscopy and Quantum Chemical Studies
- Photoreceptor and optogenetics research
- Photochemistry and Electron Transfer Studies
- Mass Spectrometry Techniques and Applications
- Electron Spin Resonance Studies
- Advanced Chemical Physics Studies
- Photosynthetic Processes and Mechanisms
- Advanced NMR Techniques and Applications
- Quantum, superfluid, helium dynamics
Nanyang Technological University
2019-2022
The “hole” story of water ionization direct observation the cationic hole H 2 O + that is formed in liquid after has been a long-standing experimental challenge. Previous attempts using optical and ultraviolet techniques have failed to reveal its key spectroscopic signature during ultrafast transformation into OH radical. Loh et al. address this gap by intense, x-ray pulses from an free electron laser at ∼530 volts. They found compelling evidence for formation decay radical proton transfer...
Resonant inelastic x-ray scattering (RIXS) provides remarkable opportunities to interrogate ultrafast dynamics in liquids. Here we use RIXS study the fundamentally and practically important hydroxyl radical liquid water, OH(aq). Impulsive ionization of pure water produced a short-lived population OH(aq), which was probed using femtosecond x-rays from an free-electron laser. We find that reveals localized electronic transitions are masked ultraviolet absorption spectrum by strong...
Abstract The elementary processes that accompany the interaction of ionizing radiation with biologically relevant molecules are fundamental importance. However, ultrafast structural rearrangement dynamics induced by ionization biomolecules in aqueous solution remain hitherto unknown. Here, we employ femtosecond optical pump-probe spectroscopy to elucidate vibrational wave packet follow photodetachment phenoxide, a mimic tyrosine, solution. Photodetachment phenoxide leads phenoxyl radical...
Abstract A unified picture of the electronic relaxation dynamics ionized liquid water has remained elusive despite decades study. Here, we employ sub-two-cycle visible to short-wave infrared pump-probe spectroscopy and ab initio nonadiabatic molecular simulations reveal that excess electron injected into conduction band (CB) undergoes sequential hydrated s ground state via an intermediate state, identified as p excited state. The measured CB -electron lifetimes are 0.26 ± 0.02 ps 62 10 fs,...
The phenylalanine radical (Phe˙) has been proposed to mediate biological electron transport (ET) and exhibit long-lived electronic coherences following attosecond photoionization. However, the coupling of ultrafast structural reorganization oxidation/ionization biomolecules such as remains unexplored. Moreover, studies ET involving Phe˙ are hindered by its hitherto unobserved spectrum. Here, we report spectroscopic observation coherent vibrational dynamics aqueous Phe˙, prepared sub-6 fs...
Ultrafast vibrational wave packet dynamics of the tyrosyl radical anion provide insight into sub-picosecond structural rearrangements induced by ionizing radiation.
The study of the photodetachment amino acids in aqueous solution is pertinent to understanding elementary processes that follow interaction ionizing radiation with biological matter. In case tryptophan, tryptophan radical produced by electron ejection also plays an important role numerous redox reactions biology, although studies its ultrafast molecular dynamics are limited. Here, we employ femtosecond optical pump-probe spectroscopy elucidate structural rearrangement accompany anion...
Proton transfer (PT) reactions are fundamental to numerous chemical and biological processes. While sub-picosecond PT involving electronically excited states has been extensively studied, little is known about ultrafast triggered by photoionization. Here, we employ femtosecond optical pump-probe spectroscopy quantum dynamics calculations investigate the proton of aqueous phenol radical cation (PhOH˙+). Analysis vibrational wave packet reveals unusually short dephasing times 0.18 ± 0.02 ps...
Correction for ‘Ultrafast vibrational wave packet dynamics of the aqueous tyrosyl radical anion induced by photodetachment’ Muhammad Shafiq Bin Mohd Yusof et al. , Phys. Chem. 2021, 23 18525–18534, DOI: 10.1039/D1CP02975D.