A5035631231- Enzyme Structure and Function
- Magnetism in coordination complexes
- Photoreceptor and optogenetics research
- Advanced X-ray Imaging Techniques
- Electron Spin Resonance Studies
- Advanced Electron Microscopy Techniques and Applications
- Supramolecular Self-Assembly in Materials
- Photochromic and Fluorescence Chemistry
- Particle Accelerators and Free-Electron Lasers
- Biochemical and Molecular Research
- Atomic and Molecular Physics
- Organic and Molecular Conductors Research
- Chemical Reactions and Isotopes
- Metal-Catalyzed Oxygenation Mechanisms
- X-ray Spectroscopy and Fluorescence Analysis
- Copper-based nanomaterials and applications
- Magnetic properties of thin films
- Light effects on plants
- Spectroscopy and Quantum Chemical Studies
- Lanthanide and Transition Metal Complexes
- Protein Structure and Dynamics
- Molecular spectroscopy and chirality
- Electrohydrodynamics and Fluid Dynamics
- Surface Modification and Superhydrophobicity
- Porphyrin Metabolism and Disorders
University of Toronto
2016-2025
Paul Scherrer Institute
2023-2024
Max Planck Institute for the Structure and Dynamics of Matter
2019
The advent of ultrafast highly brilliant coherent X-ray free-electron laser sources has driven the development novel structure-determination approaches for proteins, and promises visualization protein dynamics on sub-picosecond timescales with full atomic resolution. Significant efforts are being applied to sample-delivery systems that allow these unique be most efficiently exploited high-throughput serial femtosecond crystallography. Here, next iteration a fixed-target crystallography chip...
Abstract Photoexcitation of spin crossover (SCO) complexes can trigger extensive electronic transitions and transformation molecular structure. However, the precise nature associated ultrafast structural dynamics remains elusive, especially in solid state. Here, we studied a single‐crystal SCO material with femtosecond electron diffraction (FED). The unique capability FED allows us to directly probe atomic motions track changes within crystal lattice. By monitoring time‐dependent Bragg...
For the two proteins myoglobin and fluoroacetate dehalogenase, we present a systematic comparison of crystallographic diffraction data collected by serial femtosecond (SFX) synchrotron crystallography (SSX). To maximize comparability, used same batch micron-sized crystals, sample delivery device, analysis software. Overall figures merit indicate that both radiation sources are equivalent quality. proteins, reasonable statistics can be obtained with approximately 5000 room-temperature images...
A fixed-target approach to high-throughput room-temperature serial synchrotron crystallography with oscillation is described. Patterned silicon chips microwells provide high crystal-loading density an extremely hit rate. The microfocus, undulator-fed beamline at CHESS, which has compound refractive optics and a fast-framing detector, was built optimized for this experiment. method described here collects 1–5° of data per crystal room temperature fast (10° s −1 ) rates translation times,...
Abstract One of the most basic molecular photophysical processes is that spin transitions and intersystem crossing between excited states surfaces. The change in affects spatial distribution electron density through orbit coupling interaction. subsequent nuclear reorganization reports on full extent induced distribution, which can be treated similarly to intramolecular charge transfer with effective reaction coordinates depicting transition. Here, single-crystal [Fe II (bpy) 3 ](PF 6 ) 2 , a...
Given their nanoscale dimensions, colloidal semiconductor nanocrystals provide unique systems for investigating the dynamics controlling surface chemistry and fundamental issues regarding lattice reorganization upon changes in electron distribution. These are particularly amenable to ultrafast probes, offering an atomic level picture of involved following photoexcitation. Here, we study lead sulfide (PbS) quantum dots with diffraction characterize motions high-intensity Short-range...
Abstract A detailed understanding of the ultrafast dynamics halogen-bonded materials is desired for designing supramolecular and tuning various electronic properties by external stimuli. Here, a prototypical multifunctional material containing spin crossover (SCO) cations paramagnetic radical anions studied as model system photo-switchable SCO hybrid systems using electron diffraction two complementary optical spectroscopic techniques. Our results reveal sequential from to dimer softening,...
Abstract Photoexcitation of spin crossover (SCO) complexes can trigger extensive electronic transitions and transformation molecular structure. However, the precise nature associated ultrafast structural dynamics remains elusive, especially in solid state. Here, we studied a single‐crystal SCO material with femtosecond electron diffraction (FED). The unique capability FED allows us to directly probe atomic motions track changes within crystal lattice. By monitoring time‐dependent Bragg...
Isomerization through stereochemical changes and modulation in bond order conjugation are processes that occur ubiquitously diverse chemical systems for pho- tochromic spirocompounds, it imparts them their functionality as phototransformable molecules. However, these transformations have been notoriously challenging to observe crystals due steric hindrance but necessary ingredients the development of reversible spiro-based crystalline devices. Here we report detection spectroscopic...
The ability to freely control the polarization of X-rays enables measurement techniques relying on circular or linear dichroism, which have become indispensable tools for characterizing properties chiral molecules magnetic structures. Therefore, demand in X-ray free-electron lasers is increasing enable polarization-sensitive dynamical studies ultrafast time scales. soft branch Athos SwissFEL was designed with aim providing adjustable and arbitrary by building its undulator solely from...
Isomerisation through stereochemical changes and modulation in bond order conjugation are processes that occur ubiquitously diverse chemical systems for photochromic spirocompounds, it imparts them their functionality as phototransformable molecules. However, these transformations have been notoriously challenging to observe crystals due steric hindrance but necessary ingredients the development of reversible spiro-based crystalline devices. Here, we report detection spectroscopic signatures...
Nonlinear wave mixing in the X-ray range can provide valuable insights into structural and electron dynamics of atomic molecular systems on ultrafast time scales, with state- site-selectivity resolution. This promising experimental toolbox was so far limited by requiring at least one near-visible laser, thus preventing core-shell two-dimensional spectroscopy. In this work, we demonstrate generation background-free all-X-ray four-wave (XFWM) signals from a dilute gaseous sample (Ne). The...
We present absorption spectra of thin, free-flowing liquid sheets in the vacuum ultraviolet energy range using a gas-squeezed jet. Compared to flow cells, operation without transmission windows eliminates...
Mixed EUV/X-ray - optical four-wave mixing (FWM) has been successfully demonstrated in a transient grating (TG) configuration ([1]–[3] and refs. therein). While all-EUV TG have [2], non-linear all-X-ray wave-mixing spectroscopy envisioned theoretically described, [4] but up to now the best of our knowledge, it not realized experimentally. In this work, we present all-X-ray-four-wave (XFWM) for first time. The coherent response from core inner shell electrons an atomic gas (Ne) is demonstrated.
Abstract For the two proteins myoglobin (MB) and fluoroacetate dehalogenase (FAcD), we present a systematic comparison of crystallographic diffraction data collected by serial femtosecond (SFX) synchrotron crystallography (SSX). To maximize comparability, used same batch crystals, sample delivery device, as well analysis software. Overall figures merit indicate that both radiation sources are equivalent quality. reasonable statistics can be obtained with approximately 5000 room temperature...
Sparse Data in Serial MicrocrystallographyThere is a growing interest pursuing serial microcrystallography (SMX) experiments at existing storage ring (SR) sources.For very small crystals, radiation damage occurs before sufficient diffraction recorded to determine the orientation of crystal.The challenge merge data from large number such "sparse" frames order measure full reciprocal space intensity.With EMC algorithm, we show that diffracted intensity crystal can still be reconstructed even...
Photoinduced spin transitions are studied by femtosecond electron diffraction to understand ultrafast structural dynamics associated with intersystem crossing. The results indicate the reorganization occurs within 2.3 ps, as metal-ligand bond distribution narrows during intramolecular vibrational energy redistribution.
Multifunctional spin crossover (SCO) complexes provide control over electronic properties of anions. Here, we study a prototypical complex to understand ultrafast reaction pathways and transitional structures open way for fast responsive multi-level photoswitches.