I24-Microfocus Macromolecular Crystallography
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Peter
Smyth
,
Sofia
Jaho
,
Lewis J.
Williams
,
Gabriel
Karras
,
Ann
Fitzpatrick
,
Amy J.
Thompson
,
Sinan
Battah
,
Danny
Axford
,
Sam
Horrell
,
Marina
Lucic
,
Kotone
Ishihara
,
Machika
Kataoka
,
Hiroaki
Matsuura
,
Kanji
Shimba
,
Kensuke
Tono
,
Takehiko
Tosha
,
Hiroshi
Sugimoto
,
Shigeki
Owada
,
Michael A.
Hough
,
Jonathan A. R.
Worrall
,
Robin L.
Owen
Diamond Proposal Number(s):
[18565, 28583, 27313]
Open Access
Abstract: Time-resolved X-ray crystallography is undergoing a renaissance due to the development of serial crystallography at synchrotron and XFEL beamlines. Crucial to such experiments are efficient and effective methods for uniformly initiating time-dependent processes within microcrystals, such as ligand binding, enzymatic reactions or signalling. A widely applicable approach is the use of photocaged substrates, where the photocage is soaked into the crystal in advance and then activated using a laser pulse to provide uniform initiation of the reaction throughout the crystal. This work characterizes photocage release of nitric oxide and binding of this ligand to two heme protein systems, cytochrome c′-β and dye-decolourizing peroxidase B using a fixed target sample delivery system. Laser parameters for photoactivation are systematically explored, and time-resolved structures over timescales ranging from 100 µs to 1.4 s using synchrotron and XFEL beamlines are described. The effective use of this photocage for time-resolved crystallography is demonstrated and appropriate illumination conditions for such experiments are determined.
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Sep 2025
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I18-Microfocus Spectroscopy
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Gabriel
Karras
,
Stuart
Bartlett
,
Edward
Bowman
,
Sam
Liewis
,
Ben
Coulson
,
Ann
Fitzpatrick
,
Lauren
Hatcher
,
Konstantin
Ignatyev
,
Mark
Warren
,
Michael W
George
,
Andrew J.
Dent
Abstract: We demonstrate a portable fs laser system, used for optical-pump Xray-probe experiments in Diamond Light Source and its application in the areas of coordination chemistry and photo-induced linkage isomerization using X-ray spectroscopy and diffraction.
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May 2025
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B21-High Throughput SAXS
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Beatrice E.
Jones
,
Ann
Fitzpatrick
,
Kieran
Fowell
,
Charlotte J. C.
Edwards-Gayle
,
Nikul
Khunti
,
Katsuaki
Inoue
,
Steven
Daniels
,
Eugene
Williams
,
Camille
Blayo
,
Rachel C.
Evans
,
Nathan
Cowieson
Open Access
Abstract: Beamline B21 at the Diamond Light Source synchrotron in the UK is a small-angle X-ray scattering (SAXS) beamline that specializes in high-throughput measurements via automated sample delivery systems. A system has been developed whereby a sample can be illuminated by a focused beam of light coincident with the X-ray beam. The system is compatible with the highly automated sample delivery system at the beamline and allows a beamline user to select a light source from a broad range of wavelengths across the UV and visible spectrum and to control the timing and duration of the light pulse with respect to the X-ray exposure of the SAXS measurement. The intensity of the light source has been characterized across the wavelength range enabling experiments where a quantitative measure of dose is important. Finally, the utility of the system is demonstrated via measurement of several light-responsive samples.
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Jul 2024
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I19-Small Molecule Single Crystal Diffraction
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Diamond Proposal Number(s):
[29891, 26668]
Open Access
Abstract: Titanium-oxo clusters can undergo photochemical reactions under UV light, resulting in the reduction of the titanium-oxo core and oxidation of surface ligands. This is an important step in photocatalytic processes in light-absorbing Ti/O-based clusters, metal–organic frameworks, and (nano)material surfaces; however, studying the direct outcome of this photochemical process is challenging due to the fragility of the immediate photoproducts. In this report, titanium-oxo clusters [TiO(OiPr)(L)]n (n = 4, L = O2PPh2, or n = 6, L = O2CCH2tBu) undergo a two-electron photoredox reaction in the single-crystal state via an irreversible single-crystal to single-crystal (SC-SC) transformation initiated by a UV laser. The process is monitored by single crystal X-ray diffraction revealing the photoreduction of the cluster with coproduction of an (oxidized) acetone ligand, which is retained in the structure as a ligand to Ti(3+). The results demonstrate that photochemistry of inorganic molecules can be studied in the single crystal phase, allowing characterization of photoproducts which are unstable in the solution phase.
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Jun 2024
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I03-Macromolecular Crystallography
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Christopher D. M.
Hutchison
,
James
Baxter
,
Ann
Fitzpatrick
,
Gabriel
Dorlhiac
,
Alisia
Fadini
,
Samuel
Perrett
,
Karim
Maghlaoui
,
Salomé
Bodet Lefèvre
,
Violeta
Cordon-Preciado
,
Josie L.
Ferreira
,
Volha U.
Chukhutsina
,
Douglas
Garratt
,
Jonathan
Barnard
,
Gediminas
Galinis
,
Flo
Glencross
,
Rhodri M.
Morgan
,
Sian
Stockton
,
Ben
Taylor
,
Letong
Yuan
,
Matthew G.
Romei
,
Chi-Yun
Lin
,
Jon P.
Marangos
,
Marius
Schmidt
,
Viktoria
Chatrchyan
,
Tiago
Buckup
,
Dmitry
Morozov
,
Jaehyun
Park
,
Sehan
Park
,
Intae
Eom
,
Minseok
Kim
,
Dogeun
Jang
,
Hyeongi
Choi
,
Hyojung
Hyun
,
Gisu
Park
,
Eriko
Nango
,
Rie
Tanaka
,
Shigeki
Owada
,
Kensuke
Tono
,
Daniel P.
Deponte
,
Sergio
Carbajo
,
Matt
Seaberg
,
Andrew
Aquila
,
Sebastien
Boutet
,
Anton
Barty
,
So
Iwata
,
Steven G.
Boxer
,
Gerrit
Groenhof
,
Jasper J.
Van Thor
Diamond Proposal Number(s):
[22819, 17221]
Open Access
Abstract: The photoisomerization reaction of a fluorescent protein chromophore occurs on the ultrafast timescale. The structural dynamics that result from femtosecond optical excitation have contributions from vibrational and electronic processes and from reaction dynamics that involve the crossing through a conical intersection. The creation and progression of the ultrafast structural dynamics strongly depends on optical and molecular parameters. When using X-ray crystallography as a probe of ultrafast dynamics, the origin of the observed nuclear motions is not known. Now, high-resolution pump–probe X-ray crystallography reveals complex sub-ångström, ultrafast motions and hydrogen-bonding rearrangements in the active site of a fluorescent protein. However, we demonstrate that the measured motions are not part of the photoisomerization reaction but instead arise from impulsively driven coherent vibrational processes in the electronic ground state. A coherent-control experiment using a two-colour and two-pulse optical excitation strongly amplifies the X-ray crystallographic difference density, while it fully depletes the photoisomerization process. A coherent control mechanism was tested and confirmed the wave packets assignment.
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Aug 2023
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I18-Microfocus Spectroscopy
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Martin V.
Appleby
,
Rory A.
Cowin
,
Iona
Ivalo
,
Samantha L.
Peralta-Arriaga
,
Craig C.
Robertson
,
Stuart
Bartlett
,
Ann
Fitzpatrick
,
Andrew
Dent
,
Gabriel
Karras
,
Sofia
Diaz-Moreno
,
Dimitri
Chekulaev
,
Julia A.
Weinstein
Diamond Proposal Number(s):
[28403, 30784]
Open Access
Abstract: The study aims to understand the role of the transient bonding in the interplay between the structural and electronic changes in heteroleptic Cu(I) diimine diphosphine complexes. This is an emerging class of photosensitisers which absorb in the red region of the spectrum, whilst retaining a sufficiently long excited state lifetime. Here, the dynamics of these complexes are explored by transient absorption (TA) and time-resolved infrared (TRIR) spectroscopy, which reveal ultrafast intersystem crossing and structural distortion occurring. Two potential mechanisms affecting excited state decay in these complexes involve a transient formation of a solvent adduct, made possible by the opening up of the Cu coordination centre in the excited state due to structural distortion, and by a transient coordination of the O-atom of the phosphine ligand to the copper center. X-ray absorption studies of the ground electronic state have been conducted as a prerequisite for the upcoming X-ray spectroscopy studies which will directly determine structural dynamics. The potential for these complexes to be used in bimolecular applications is confirmed by a significant yield of singlet oxygen production.
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Jul 2023
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I06-Nanoscience (XPEEM)
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Allan S.
Johnson
,
Daniel
Perez-Salinas
,
Khalid M.
Siddiqui
,
Sungwon
Kim
,
Sungwook
Choi
,
Klara
Volckaert
,
Paulina E.
Majchrzak
,
Soeren
Ulstrup
,
Naman
Agarwal
,
Kent
Hallman
,
Richard F.
Haglund
,
Christian M.
Günther
,
Bastian
Pfau
,
Stefan
Eisebitt
,
Dirk
Backes
,
Francesco
Maccherozzi
,
Ann
Fitzpatrick
,
Sarnjeet S.
Dhesi
,
Pierluigi
Gargiani
,
Manuel
Valvidares
,
Nongnuch
Artrith
,
Frank
De Groot
,
Hyeongi
Choi
,
Dogeun
Jang
,
Abhishek
Katoch
,
Soonnam
Kwon
,
Sang Han
Park
,
Hyunjung
Kim
,
Simon E.
Wall
Diamond Proposal Number(s):
[22048]
Open Access
Abstract: Using light to control transient phases in quantum materials is an emerging route to engineer new properties and functionality, with both thermal and non-thermal phases observed out of equilibrium. Transient phases are expected to be heterogeneous, either through photo-generated domain growth or by generating topological defects, and this impacts the dynamics of the system. However, this nanoscale heterogeneity has not been directly observed. Here we use time- and spectrally resolved coherent X-ray imaging to track the prototypical light-induced insulator-to-metal phase transition in vanadium dioxide on the nanoscale with femtosecond time resolution. We show that the early-time dynamics are independent of the initial spatial heterogeneity and observe a 200 fs switch to the metallic phase. A heterogeneous response emerges only after hundreds of picoseconds. Through spectroscopic imaging, we reveal that the transient metallic phase is a highly orthorhombically strained rutile metallic phase, an interpretation that is in contrast to those based on spatially averaged probes. Our results demonstrate the critical importance of spatially and spectrally resolved measurements for understanding and interpreting the transient phases of quantum materials.
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Dec 2022
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I06-Nanoscience (XPEEM)
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Andrea
Ronchi
,
Paolo
Franceschini
,
Andrea
De Poli
,
Pia
Homm
,
Ann
Fitzpatrick
,
Francesco
Maccherozzi
,
Gabriele
Ferrini
,
Francesco
Banfi
,
Sarnjeet S.
Dhesi
,
Mariela
Menghini
,
Michele
Fabrizio
,
Jean-Pierre
Locquet
,
Claudio
Giannetti
Diamond Proposal Number(s):
[18897, 21700]
Open Access
Abstract: Mott transitions in real materials are first order and almost always associated with lattice distortions, both features promoting the emergence of nanotextured phases. This nanoscale self-organization creates spatially inhomogeneous regions, which can host and protect transient non-thermal electronic and lattice states triggered by light excitation. Here, we combine time-resolved X-ray microscopy with a Landau-Ginzburg functional approach for calculating the strain and electronic real-space configurations. We investigate V2O3, the archetypal Mott insulator in which nanoscale self-organization already exists in the low-temperature monoclinic phase and strongly affects the transition towards the high-temperature corundum metallic phase. Our joint experimental-theoretical approach uncovers a remarkable out-of-equilibrium phenomenon: the photo-induced stabilisation of the long sought monoclinic metal phase, which is absent at equilibrium and in homogeneous materials, but emerges as a metastable state solely when light excitation is combined with the underlying nanotexture of the monoclinic lattice.
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Jun 2022
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I06-Nanoscience (XPEEM)
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K. R.
Beyerlein
,
A.
Disa
,
M.
Först
,
M.
Henstridge
,
T.
Gebert
,
T.
Forrest
,
A.
Fitzpatrick
,
C.
Dominguez
,
J.
Fowlie
,
M.
Gibert
,
J.-M.
Triscone
,
S. S.
Dhesi
,
A.
Cavalleri
Diamond Proposal Number(s):
[17605]
Open Access
Abstract: We use resonant soft x-ray diffraction to track the photoinduced dynamics of the antiferromagnetic structure in a
NdNi
O
3
thin film. Femtosecond laser pulses with a photon energy of 0.61 eV, resonant with electron transfer between long-bond and short-bond nickel sites, are used to excite the material and drive an ultrafast insulator-metal transition. Polarization-sensitive soft x-ray diffraction, resonant to the nickel
L
3
edge, then probes the evolution of the underlying magnetic spiral as a function of time delay with 80 ps time resolution. By modeling the azimuthal dependence of the scattered intensity for different linear x-ray polarizations, we benchmark the changes of the local magnetic moments and the spin alignment. The measured changes are consistent with a reduction of the long-bond site magnetic moments and an alignment of the spins towards a more collinear structure at early time delays.
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Jul 2020
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B22-Multimode InfraRed imaging And Microspectroscopy
Optics
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Open Access
Abstract: Vibrational microspectroscopy via Fourier transform infrared (FTIR) faces an experimental trade-off among the signal to noise ratio (SNR), acquisition time, spatial resolution, and sample coverage. This is mainly associated with broadband source type: e.g. low brightness thermal sources with high flux for large field of view imaging at low resolution, or low ´etendue of synchrotron radiation infrared (SRIR) for diffraction-limited scanning mi- croanalysis at high magnification.1 Adaptive optics (AO), in this case deformable mirror (DM), is a potent tool in tackling the problem by modulating the intensity of high brightness structured SRIR beam toward a homo- geneous field illumination for IR imaging at high magnification. The latter is required for an efficient coupling of SRIR source to a multi-pixel detector such as focal plane array (FPA).2 Additionally, DM enables to achieve different shapes, optimized for different Cassegrain IR objective. Regardless, the quality of the generated beam relies upon the performance of the adaptive elements, i.e. actuators and their linear and reproducible response to the applied voltage. Moreover, the beam shaping capability of a single DM in controlling light beam position and angle is limited by its actuators influence function. In this work, we implemented two DMs for intensity shaping for the complex SRIR beam. A variation of multi-conjugate AO is implemented to characterize the performance of DMs and their actuators transfer function at multiple locations. An IR sensitive microbolometer array has been optically conjugated to the focal plane of individual actuators and the far-field of DM, in order to probe the corresponding actuating response. By analysing each actuator’s response individually, a measure of linear independence, uniformity in response, and cross-coupling can be obtained in a spectral range, from visible to near and mid IR. Additionally, by assembling the vectorized version of each actuator response, the transfer matrix can be formed. This matrix describes the relationship between the actuation effect on the beam and the response of the IR microbolometer, at the given conjugate planes. Based on such discussion, we assess the stability of the deformable mirror for open-loop (i.e. without feedback) operation.
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May 2020
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