B22-Multimode InfraRed imaging And Microspectroscopy
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Arun S.
Babal
,
Lorenzo
Donà
,
Matthew R.
Ryder
,
Kirill
Titov
,
Abhijeet K.
Chaudhari
,
Zhixin
Zeng
,
Chris S.
Kelley
,
Mark D.
Frogley
,
Gianfelice
Cinque
,
Bartolomeo
Civalleri
,
Jin-chong
Tan
Diamond Proposal Number(s):
[14902]
Abstract: Research on the broadband dielectric response of metal-organic frameworks (MOFs) is an emergent field that could yield exciting device applications, such as smart optoelectronics, terahertz sensors, high-speed telecommunications and microelectronics. Hitherto, a detailed understanding of the physical mechanisms controlling the frequency-dependent dielectric and optical behavior of MOFs is lacking because a large number of studies have focused only on static dielectric constants. Herein we employed high-resolution spectroscopic techniques in combination with periodic ab initio density functional theory (DFT) calculations to establish the different polarization processes for a porous copper-based MOF, termed HKUST-1. We used alternating current measurements to determine its dielectric response between 4 Hz and 1.5 MHz where orientational polarization is predominant, while synchrotron infrared (IR) reflectance was used to probe the far-IR, mid-IR, and near-IR dielectric response across the 1.2 THz to 150 THz range (ca. 40 – 5000 cm-1) where vibrational and optical polarizations are principal contributors to its dielectric permittivity. We demonstrate the role of pressure on the evolution of broadband dielectric response, where THz vibrations reveal distinct blue and red shifts of phonon modes from structural deformation of the copper paddle-wheel and the organic linker, respectively. We also investigated the effect of temperature on dielectric constants in the MHz region pertinent to microelectronics, to study temperature-dependent dielectric losses via dissipation in an alternating electric field. The DFT calculations offer insights into the physical mechanisms responsible for dielectric transitions observed in the experiments and enable us to explain the frequency shifts phenomenon detected under pressure. Together, the experiments and theory have enabled us to glimpse into the complex dielectric response and mechanisms underpinning a prototypical MOF subject to pressure, temperature, and vast frequencies.
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Nov 2019
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B22-Multimode InfraRed imaging And Microspectroscopy
I11-High Resolution Powder Diffraction
I12-JEEP: Joint Engineering, Environmental and Processing
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Harry G. W.
Godfrey
,
Lydia
Briggs
,
Xue
Han
,
William J. F.
Trenholme
,
Christopher
Morris
,
Mathew
Savage
,
Louis
Kimberley
,
Oxana
Magdysyuk
,
Michael
Drakopoulos
,
Claire A.
Murray
,
Chiu C.
Tang
,
Mark D.
Frogley
,
Gianfelice
Cinque
,
Sihai
Yang
,
Martin
Schroeder
Diamond Proposal Number(s):
[11278]
Open Access
Abstract: Understanding the mechanism of assembly and function of metal-organic frameworks (MOFs) is important for the development of practical materials. Herein, we report a time-resolved diffraction analysis of the kinetics of formation of a robust MOF, MFM-300(Fe), which shows high adsorption capacity for CO2 (9.55 mmol g−1 at 293 K and 20 bar). Applying the Avrami-Erofe’ev and the two-step kinetic Finke-Watzky models to in situ high-energy synchrotron X-ray powder diffraction data obtained during the synthesis of MFM-300(Fe) enables determination of the overall activation energy of formation (50.9 kJ mol−1), the average energy of nucleation (56.7 kJ mol−1), and the average energy of autocatalytic growth (50.7 kJ mol−1). The synthesis of MFM-300(Fe) has been scaled up 1000-fold, enabling the successful breakthrough separations of the CO2/N2 mixture in a packed-bed with a selectivity for CO2/N2 of 21.6. This study gives an overall understanding for the intrinsic behaviors of this MOF system, and we have determined directly the binding domains and dynamics for adsorbed CO2 molecules within the pores of MFM-300(Fe).
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Nov 2019
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B22-Multimode InfraRed imaging And Microspectroscopy
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Gemma L.
Smith
,
Jennifer E.
Eyley
,
Xue
Han
,
Xinran
Zhang
,
Jiangnan
Li
,
Nicholas M.
Jacques
,
Harry G. W.
Godfrey
,
Stephen P.
Argent
,
Laura J.
Mccormick Mcpherson
,
Simon J.
Teat
,
Yongqiang
Cheng
,
Mark D.
Frogley
,
Gianfelice
Cinque
,
Sarah
Day
,
Chiu C.
Tang
,
Timothy L.
Easun
,
Svemir
Rudic
,
Anibal J.
Ramirez-cuesta
,
Sihai
Yang
,
Martin
Schroeder
Abstract: Emissions of SO2 from flue gas and marine transport have detrimental impacts on the environment and human health, but SO2 is also an important industrial feedstock if it can be recovered, stored and transported efficiently. Here we report the exceptional adsorption and separation of SO2 in a porous material, [Cu2(L)] (H4L = 4′,4‴-(pyridine-3,5-diyl)bis([1,1′-biphenyl]-3,5-dicarboxylic acid)), MFM-170. MFM-170 exhibits fully reversible SO2 uptake of 17.5 mmol g−1 at 298 K and 1.0 bar, and the SO2 binding domains for trapped molecules within MFM-170 have been determined. We report the reversible coordination of SO2 to open Cu(ii) sites, which contributes to excellent adsorption thermodynamics and selectivities for SO2 binding and facile regeneration of MFM-170 after desorption. MFM-170 is stable to water, acid and base and shows great promise for the dynamic separation of SO2 from simulated flue gas mixtures, as confirmed by breakthrough experiments.
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Oct 2019
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B22-Multimode InfraRed imaging And Microspectroscopy
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Xinchen
Kang
,
Kai
Lyu
,
Lili
Li
,
Jiangnan
Li
,
Louis
Kimberley
,
Bin
Wang
,
Lifei
Liu
,
Yongqiang
Cheng
,
Mark D.
Frogley
,
Svemir
Rudic
,
Anibal J.
Ramirez-cuesta
,
Robert A. W.
Dryfe
,
Buxing
Han
,
Sihai
Yang
,
Martin
Schroder
Diamond Proposal Number(s):
[19171]
Open Access
Abstract: Incorporation of mesopores and active sites into metal-organic framework (MOF) materials to uncover new efficient catalysts is a highly desirable but challenging task. We report the first example of a mesoporous MOF obtained by templated electrosynthesis using an ionic liquid as both electrolyte and template. The mesoporous Cu(II)-MOF MFM-100 has been synthesised in 100 seconds at room temperature, and this material incorporates crystal defects with uncoupled Cu(II) centres as evidenced by confocal fluorescence microscopy and electron paramagnetic resonance spectroscopy. MFM-100 prepared in this way shows exceptional catalytic activity for the aerobic oxidation of alcohols to produce aldehydes in near quantitative yield and selectivity under mild conditions, as well as having excellent stability and reusability over repeated cycles. The catalyst-substrate binding interactions have been probed by inelastic neutron scattering. This study offers a simple strategy to create mesopores and active sites simultaneously via electrochemical formation of crystal defects to promote efficient catalysis using MOFs.
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Oct 2019
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B22-Multimode InfraRed imaging And Microspectroscopy
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F.
Domenici
,
A.
Capocefalo
,
F.
Brasili
,
A.
Bedini
,
C.
Giliberti
,
R.
Palomba
,
I.
Silvestri
,
S.
Scarpa
,
S.
Morrone
,
G.
Paradossi
,
M. D.
Frogley
,
G.
Cinque
Diamond Proposal Number(s):
[8055]
Open Access
Abstract: Ultrasound (US) induced transient membrane permeabilisation has emerged as a hugely promising tool for the delivery of exogenous vectors through the cytoplasmic membrane, paving the way to the design of novel anticancer strategies by targeting functional nanomaterials to specific biological sites. An essential step towards this end is the detailed recognition of suitably marked nanoparticles in sonoporated cells and the investigation of the potential related biological effects. By taking advantage of Synchrotron Radiation Fourier Transform Infrared micro-spectroscopy (SR-microFTIR) in providing highly sensitive analysis at the single cell level, we studied the internalisation of a nanoprobe within fibroblasts (NIH-3T3) promoted by low-intensity US. To this aim we employed 20 nm gold nanoparticles conjugated with the IR marker 4-aminothiophenol. The significant Surface Enhanced Infrared Absorption provided by the nanoprobes, with an absorbance increase up to two orders of magnitude, allowed us to efficiently recognise their inclusion within cells. Notably, the selective and stable SR-microFTIR detection from single cells that have internalised the nanoprobe exhibited clear changes in both shape and intensity of the spectral profile, highlighting the occurrence of biological effects. Flow cytometry, immunofluorescence and murine cytokinesis-block micronucleus assays confirmed the presence of slight but significant cytotoxic and genotoxic events associated with the US-nanoprobe combined treatments. Our results can provide novel hints towards US and nanomedicine combined strategies for cell spectral imaging as well as drug delivery-based therapies.
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Aug 2019
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B22-Multimode InfraRed imaging And Microspectroscopy
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Diamond Proposal Number(s):
[13725, 16257, 20906]
Abstract: Synchrotron infrared microspectroscopy has identified with high temporal resolution (down to 0.25 s) the initial events occurring when methanol vapour is contacted with a crystal of zeolite HZSM-5. The first alkenes are generated directly from methoxy groups formed at the acid sites via their deprotonation. These alkenes can either desorb directly or oligomerise and cyclise to form dimethylcyclopentenyl cations. The oligomeric and dimethylcyclopentenyl cations are the first major components of the hydrocar-bon pool that precede aromatic hydrocarbons and lead to indirect alkene formation. This is the first direct observation of these events in real time.
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Jun 2019
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B18-Core EXAFS
B22-Multimode InfraRed imaging And Microspectroscopy
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Kirill
Titov
,
Dmitry
Eremin
,
Alexey S.
Kashin
,
Roberto
Boada Romero
,
Barbara
Souza
,
Chris S.
Kelley
,
Mark D.
Frogley
,
Gianfelice
Cinque
,
Diego
Gianolio
,
Giannantonio
Cibin
,
Svemir
Rudic
,
Valentine P
Ananikov
,
Jin-chong
Tan
Diamond Proposal Number(s):
[14902, 17146]
Abstract: A catalytic system based on OX-1 metal-organic framework nanosheets is reported, incorporating catalytically active palladium (Pd) species. The Pd@OX-1 guest@host system is rapidly synthesised via a facile single-pot supramolecular assembly method, with the possibility of controlling the Pd loading. The structures of the re-sulting framework and of the active Pd species before and after catalytic reactions are studied in detail using a wide variety of techniques including synchrotron radiation infrared spectroscopy, inelastic neutron scattering and X-ray absorption spectroscopy. Crystals of the resulting Pd@OX-1 composite material contain predomi-nantly atomic and small cluster Pd species, which selectively reside on benzene rings of the benzenedicarbox-ylate (BDC) linkers. The composites are shown to efficiently catalyse the Suzuki coupling and Heck arylation reactions under a variety of conditions. Pd@OX-1 further shows potential to be recycled for at least five cycles of each reaction as well as an ability to recapture active Pd species during both catalytic reactions.
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Feb 2019
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B18-Core EXAFS
B22-Multimode InfraRed imaging And Microspectroscopy
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Ana L. M.
Batista De Carvalho
,
Adriana P.
Mamede
,
Asha
Dopplapudi
,
Victoria
Garcia Sakai
,
James
Doherty
,
Mark
Frogley
,
Gianfelice
Cinque
,
Peter
Gardner
,
Diego
Gianolio
,
Luis A. E.
Batista De Carvalho
,
M. Paula M.
Marques
Diamond Proposal Number(s):
[14895, 16058]
Abstract: Complementary structural and dynamical information on drug–DNA interplay has been achieved at a molecular level, for Pt/Pd-drugs, allowing a better understanding of their pharmacodynamic profile which is crucial for the development of improved chemotherapeutic agents. The interaction of two cisplatin-like dinuclear Pt(II) and Pd(II) complexes with DNA was studied through a multidisciplinary experimental approach, using quasi-elastic neutron scattering (QENS) techniques coupled with synchrotron-based extended X-ray absorption fine structure (SR-EXAFS) and Fourier-Transform Infrared Spectroscopy-Attenuated Total Reflectance (SR-FTIR-ATR). DNA extracted from drug-exposed human triple negative breast cancer cells (MDA-MB-231) was used, with a view to evaluate the effect of the unconventional antineoplastic agents on this low prognosis type of cancer. The drug impact on DNA's dynamical profile, via its hydration layer, was provided by QENS, a drug-triggered enhanced mobility having been revealed. Additionally, an onset of anharmonicity was detected for dehydrated DNA, at room temperature. Far- and mid-infrared measurements allowed the first simultaneous detection of the drugs and their primary pharmacological target, as well as the drug-prompted changes in DNA's conformation that mediate cytotoxicity. The local environment of the absorbing Pd(II) and Pt(II) centers in the drugs’ adducts with adenine, guanine and glutathione was attained by EXAFS.
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Jan 2019
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B22-Multimode InfraRed imaging And Microspectroscopy
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Diamond Proposal Number(s):
[11395, 8920]
Abstract: The design and characterisation of rectifying terahertz detectors, based on InGaAs zero-bias Schottky diodes, is reported. These uncooled devices offer a spectral detection range from tens of GHz to above 3 THz, high response speed, and the prospect of low cost for mass production and arrayed implementation. We describe the airbridged semiconductor devices, their incorporation into waveguide mounts and quasi-optical substrate lens / planar antenna structures. Noise equivalent powers of 5 pW/Hz1/2 at 100 GHz, increasing to 50 pW/Hz1/2 at 300 GHz been achieved, along with rise and fall times of tens of picoseconds. We shall discuss examples of the use of the detectors: characterising a picosecond transistor-based source, spectrally narrow and broad band sources in the laboratory and coherent THz synchrotron radiation in the range 0.15 to 1.4 THz at the MIRIAM beamline B22 on the Diamond Light Source. The latter radiation was emitted from bunches of electrons circulating in the Diamond storage ring operating in THz-dedicated low-alpha mode. Spectral information on coherent synchrotron radiation originating from a single bunch of electrons is obtained, as well as the usefulness of this for spectroscopy, is evaluated.
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Jan 2019
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B22-Multimode InfraRed imaging And Microspectroscopy
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Open Access
Abstract: In September 2017, the International Workshop on Infrared Microscopy and Spectroscopy with Accelerator-based Sources (WIRMS) paid its first visit to the UK. Organized by Diamond Light Source, a vibrant international community came together for four packed days among the spires of the historical Worcester College of Oxford University to discuss the latest developments in infrared (IR) microscopy, spectroscopy including Terra Hertz (THz), and imaging by synchrotron radiation (SR) and free electron lasers (FELs).
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Nov 2018
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