scholarly journals Exploring the capabilities of optical pump X-ray probe NEXAFS spectroscopy to track photo-induced dynamics mediated by conical intersections

2020 ◽  
Vol 221 ◽  
pp. 245-264 ◽  
Author(s):  
Francesco Segatta ◽  
Artur Nenov ◽  
Silvia Orlandi ◽  
Alberto Arcioni ◽  
Shaul Mukamel ◽  
...  
Keyword(s):  
Theoretical Approach ◽  
Organic Molecules ◽  
Test Case ◽  
Conical Intersections ◽  
Present Contribution ◽  
Optical Pump ◽  
X Ray ◽  
Nexafs Spectroscopy

In the present contribution we introduce an accurate theoretical approach for the simulation of NEXAFS spectra of organic molecules, employing azobenzene as a test case.

scholarly journals Towards Poisson noise limited optical pump soft X-ray probe NEXAFS spectroscopy using a laser-produced plasma source

2019 ◽  
Vol 27 (25) ◽  
pp. 36524 ◽  
Author(s):  
Adrian Jonas ◽  
Holger Stiel ◽  
Lisa Glöggler ◽  
Diana Dahm ◽  
Katharina Dammer ◽  
...  
Keyword(s):  
Plasma Source ◽  
Poisson Noise ◽  
Optical Pump ◽  
X Ray ◽  
Nexafs Spectroscopy ◽  
Laser Produced Plasma

scholarly journals Towards Understanding Excited-State Properties of Organic Molecules Using Time-Resolved Soft X-ray Absorption Spectroscopy

2021 ◽  
Vol 22 (24) ◽  
pp. 13463
Author(s):  
Holger Stiel ◽  
Julia Braenzel ◽  
Adrian Jonas ◽  
Richard Gnewkow ◽  
Lisa Theresa Glöggler ◽  
...  
Keyword(s):  
Excited State ◽  
Absorption Spectroscopy ◽  
Density Functional ◽  
Organic Molecules ◽  
Optical Pump ◽  
Time Resolved ◽  
X Ray ◽  
Metal Free ◽  
Vis Spectroscopy ◽  
X Ray Absorption

The extension of the pump-probe approach known from UV/VIS spectroscopy to very short wavelengths together with advanced simulation techniques allows a detailed analysis of excited-state dynamics in organic molecules or biomolecular structures on a nanosecond to femtosecond time level. Optical pump soft X-ray probe spectroscopy is a relatively new approach to detect and characterize optically dark states in organic molecules, exciton dynamics or transient ligand-to-metal charge transfer states. In this paper, we describe two experimental setups for transient soft X-ray absorption spectroscopy based on an LPP emitting picosecond and sub-nanosecond soft X-ray pulses in the photon energy range between 50 and 1500 eV. We apply these setups for near-edge X-ray absorption fine structure (NEXAFS) investigations of thin films of a metal-free porphyrin, an aggregate forming carbocyanine and a nickel oxide molecule. NEXAFS investigations have been carried out at the carbon, nitrogen and oxygen K-edge as well as on the Ni L-edge. From time-resolved NEXAFS carbon, K-edge measurements of the metal-free porphyrin first insights into a long-lived trap state are gained. Our findings are discussed and compared with density functional theory calculations.

High Resolution Replication of Organoclay Surfaces

1982 ◽  
Vol 40 ◽  
pp. 576-577
Author(s):  
W. W. Barker ◽  
W. E. Rigsby ◽  
V. J. Hurst ◽  
W. J. Humphreys
Keyword(s):  
Clay Mineral ◽  
Organic Molecule ◽  
Organic Molecules ◽  
X Ray Diffraction ◽  
Xrd Pattern ◽  
X Ray ◽  
Naturally Occurring ◽  
Silicate Layers ◽  
Mineral Identification

Experimental clay mineral-organic molecule complexes long have been known and some of them have been extensively studied by X-ray diffraction methods. The organic molecules are adsorbed onto the surfaces of the clay minerals, or intercalated between the silicate layers. Natural organo-clays also are widely recognized but generally have not been well characterized. Widely used techniques for clay mineral identification involve treatment of the sample with H2 O2 or other oxidant to destroy any associated organics. This generally simplifies and intensifies the XRD pattern of the clay residue, but helps little with the characterization of the original organoclay. Adequate techniques for the direct observation of synthetic and naturally occurring organoclays are yet to be developed.

The Design of Organic Gelators Based on a Family of Bis-Ureas

1999 ◽  
Vol 604 ◽  
Author(s):  
Rosa E. Meléndez ◽  
Andrew J. Carn ◽  
Kazuki Sada ◽  
Andrew D. Hamilton
Keyword(s):  
Thermodynamic Properties ◽  
Organic Solvents ◽  
Organic Molecules ◽  
Materials Science ◽  
Crystallographic Data ◽  
Porous Solids ◽  
X Ray ◽  
Molecule Structure ◽  
Structure Activity ◽  
Potential Applications

AbstractThe use of organic molecules as gelators in certain organic solvents has been the target of recent research in materials science. The types of structures formed in the gel matrix have potential applications as porous solids that can be used as absorbents or in catalysis. We will present and discuss the organogelation properties of a family of bis-ureas. Studies presented will include a molecule structure activity relationship, thermodynamic properties, comparison to x-ray crystallographic data and potential functionalization of the gels formed by this class of compounds

scholarly journals Monitoring conical intersections in the ring opening of furan by attosecond stimulated X-ray Raman spectroscopy

2015 ◽  
Vol 3 (2) ◽  
pp. 023601 ◽  
Author(s):  
Weijie Hua ◽  
Sven Oesterling ◽  
Jason D. Biggs ◽  
Yu Zhang ◽  
Hideo Ando ◽  
...  
Keyword(s):  
Raman Spectroscopy ◽  
Ring Opening ◽  
Conical Intersections ◽  
X Ray

The conversion of smectite to illite during diagenesis: evidence from some illitic clays from bentonites and sandstones

1985 ◽  
Vol 49 (352) ◽  
pp. 393-400 ◽  
Author(s):  
P. H. Nadeau ◽  
M. J. Wilson ◽  
W. J. McHardy ◽  
J. M. Tait
Keyword(s):  
Organic Molecules ◽  
Thickness Distribution ◽  
Sedimentary Rocks ◽  
Exchangeable Cations ◽  
Diffraction Effect ◽  
X Ray Diffraction ◽  
X Ray ◽  
Depth Of Burial ◽  
Particle Thickness ◽  
Scanning Electron

AbstractDiagenetic illitic clays from seven North American bentonites of Ordovician, Devonian, and Cretaceous ages and from three subsurface North Sea sandstones of Permian and Jurassic ages have been examined by X-ray diffraction (XRD) and transmission and scanning electron microscopy (TEM and SEM). XRD indicates that the clays from the bentonites are randomly and regularly interstratified illite/smectites (I/S) with 30–90% illite layers, whereas the clays from the Jurassic and Permian sandstones are regularly interstratified I/S, with 80–90% illite layers, and illite respectively. TEM of shadowed materials shows that randomly interstratified I/S consists primarily of mixtures of elementary smectite and ‘illite’ particles (10 and 20Å thick respectively) and that regularly interstratified I/S and illite consist mainly of ‘illite’ particles 20–50 Å thick and > 50 Å thick respectively. Regularly interstratified I/S from bentonites and sandstones are similar with regard to XRD character and particle thickness distribution. These observations can be rationalized if the interstratified XRD character arises from an interparticle diffraction effect, where the smectite interlayers perceived by XRD, result from adsorption of exchangeable cations and water or organic molecules at the interfaces of particles generally < 50Å thick. A neoformation mechanism is proposed by which smectite is converted to illite with increasing depth of burial in sedimentary rocks, based on dissolution of smectite particles and the precipitation/growth of ‘illite’ particles occurring within a population of thin phyllosilicate crystals.

Evolution structurale de la nacrite en fonction de la nature des molécules organiques intercalees

2000 ◽  
Vol 33 (6) ◽  
pp. 1351-1359 ◽  
Author(s):  
A. Ben Haj Amara ◽  
H. Ben Rhaiem ◽  
A. Plançon
Keyword(s):  
Ir Spectroscopy ◽  
Hydrogen Bonds ◽  
Dimethyl Sulfoxide ◽  
Organic Molecules ◽  
Interlayer Space ◽  
X Ray Diffraction ◽  
X Ray ◽  
Intercalated Compounds ◽  
Xrd Study ◽  
Intercalation Process

Nacrite has been intercalated with two polar organic molecules: dimethyl sulfoxide (DMSO) andN-methylacetamide (NMA). The homogeneous nacrite complexes have been studied by X-ray diffraction (XRD) and infrared (IR) spectroscopy. The XRD study is based on a comparison between experimental and calculated patterns. The structures of the intercalated compounds have been determined, including the mutual positions of the layers after intercalation and the positions of the intercalated molecules in the interlayer space. It has been shown that the intercalation process causes not only a swelling of the interlayer space but also a shift in the mutual in-plane positions of the layers. This shift depends on the nature of the intercalated molecules and is related to their shape and the hydrogen bonds which are established with the surrounding surfaces. For a given molecule, the intercalation process is the same for the different polytypes of the kaolinite family. These XRD results are consistent with those of IR spectroscopy.

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