Probing hydrogen bonding orbitals: resonant inelastic soft X-ray scattering of aqueous NH3

2015 ◽  
Vol 17 (40) ◽  
pp. 27145-27153 ◽  
Author(s):  
L. Weinhardt ◽  
E. Ertan ◽  
M. Iannuzzi ◽  
M. Weigand ◽  
O. Fuchs ◽  
...  
Keyword(s):  
Hydrogen Bonding ◽  
Aqueous Ammonia ◽  
X Ray ◽  
X Ray Scattering ◽  
Ray Scattering

Resonant inelastic soft X-ray scattering was used to probe the hydrogen bonding orbitals in aqueous ammonia.

scholarly journals Vibrational Resonant Inelastic X-Ray Scattering Inliquid Acetic Acid: A Ruler for Molecular Chain Lengths

2020 ◽  
Author(s):  
Viktoriia Savchenko ◽  
Iulia-Emilia Brumboiu ◽  
Victor Kimberg ◽  
Michael Odelius ◽  
Pavel Krasnov ◽  
...  
Keyword(s):  
Molecular Structure ◽  
Hydrogen Bonding ◽  
Acetic Acid ◽  
Molecular Chain ◽  
X Ray ◽  
X Ray Scattering ◽  
Localized Excitations ◽  
Vibrational Excitations ◽  
Chain Lengths ◽  
Ray Scattering

Abstract Quenching of vibrational excitations in resonant inelastic X-ray scattering (RIXS) spectra of liquid acetic acid is observed. At the oxygen core resonance associated with localized excitations at the O-H bond, the spectra lack the typical progressionof vibrational excitations observed in RIXS spectra of comparable systems. We interpret this phenomenon as due to strong rehybridization of the unoccupied molecular orbitals as a result of hydrogen bonding. This allows us to address the molecular structure of the liquid, and to determine a lower limit for the average molecular chain length.

scholarly journals Supramolecular Dimerization in a Polymer Melt from Small-Angle X-ray Scattering and Rheology: A Miscible Model System

Polymers ◽  
2020 ◽  
Vol 12 (4) ◽  
pp. 880
Author(s):  
Mariapaola Staropoli ◽  
Margarita Kruteva ◽  
Jürgen Allgaier ◽  
Andreas Wischnewski ◽  
Wim Pyckhout-Hintzen
Keyword(s):  
Hydrogen Bonding ◽  
Small Angle ◽  
Full Range ◽  
Polymer Melt ◽  
Self Healing ◽  
Temperature Dependent ◽  
Base Pairs ◽  
X Ray ◽  
X Ray Scattering ◽  
Ray Scattering

We present a structural and dynamic study on the simplest supramolecular hetero-association, recently investigated by the authors to prepare architectural homogeneous structures in the melt state, based on the bio-inspired hydrogen-bonding of thymine/diaminotriazine (thy–DAT) base-pairs. In the combination with an amorphous low Tg poly(butylene oxide) (PBO), no micellar structures are formed, which is expected for nonpolar polymers because of noncompatibility with the highly polar supramolecular groups. Instead, a clear polymer-like transient architecture is retrieved. This makes the heterocomplementary thy–DAT association an ideal candidate for further exploitation of the hydrogen-bonding ability in the bulk for self-healing purposes, damage management in rubbers or even the development of easily processable branched polymers with built-in plasticizer. In the present work, we investigate the temperature range from Tg + 20 °C to Tg + 150 °C of an oligomeric PBO using small-angle X-ray scattering (SAXS) and linear rheology on the pure thy and pure DAT monofunctionals and on an equimolar mixture of thy/DAT oligomers. The linear rheology performed at low temperature is found to correspond to fully closed-state dimeric configurations. At intermediate temperatures, SAXS probes the equilibrium between open and closed states of the thy–DAT mixtures. The temperature-dependent association constant in the full range between open and closed H-bonds and an enhancement of the monomeric friction coefficient due to the groups is obtained. The thy–DAT association in the melt is more stable than the DAT–DAT, whereas the thy–thy association seems to involve additional long-lived interactions.

scholarly journals Hydrophilic and hydrophobic interactions in concentrated aqueous imidazole solutions: a neutron diffraction and total X-ray scattering study

2020 ◽  
Vol 22 (9) ◽  
pp. 5105-5113
Author(s):  
Laila H. Al-Madhagi ◽  
Samantha K. Callear ◽  
Sven L. M. Schroeder
Keyword(s):  
Hydrogen Bonding ◽  
Neutron Diffraction ◽  
Hydrophobic Interactions ◽  
X Ray Diffraction ◽  
X Ray ◽  
X Ray Scattering ◽  
Scattering Study ◽  
Ray Scattering

A study of 5 M aqueous imidazole solutions combining neutron and X-ray diffraction with EPSR simulations shows dominance of hydrogen-bonding between imidazole and water and negligible hydrogen-bonding between imidazole molecules.

scholarly journals In situultra-small-angle X-ray scattering study under uniaxial stretching of colloidal crystals prepared by silica nanoparticles bearing hydrogen-bonding polymer grafts

IUCrJ ◽  
2016 ◽  
Vol 3 (3) ◽  
pp. 211-218 ◽  
Author(s):  
Ryohei Ishige ◽  
Gregory A. Williams ◽  
Yuji Higaki ◽  
Noboru Ohta ◽  
Masugu Sato ◽  
...  
Keyword(s):  
Hydrogen Bonding ◽  
Small Angle ◽  
Repulsive Interaction ◽  
Face Centered Cubic ◽  
Uniaxial Stretching ◽  
X Ray ◽  
Grafted Polymer ◽  
X Ray Scattering ◽  
Ray Scattering

A molded film of single-component polymer-grafted nanoparticles (SPNP), consisting of a spherical silica core and densely grafted polymer chains bearing hydrogen-bonding side groups capable of physical crosslinking, was investigated byin situultra-small-angle X-ray scattering (USAXS) measurement during a uniaxial stretching process. Static USAXS revealed that the molded SPNP formed a highly oriented twinned face-centered cubic (f.c.c.) lattice structure with the [11−1] plane aligned nearly parallel to the film surface in the initial state. Structural analysis ofin situUSAXS using a model of uniaxial deformation induced by rearrangement of the nanoparticles revealed that the f.c.c. lattice was distorted in the stretching direction in proportion to the macroscopic strain until the strain reached 35%, and subsequently changed into other f.c.c. lattices with different orientations. The lattice distortion and structural transition behavior corresponded well to the elastic and plastic deformation regimes, respectively, observed in the stress–strain curve. The attractive interaction of the hydrogen bond is considered to form only at the top surface of the shell and then plays an effective role in cross-linking between nanoparticles. The rearrangement mechanism of the nanoparticles is well accounted for by a strong repulsive interaction between the densely grafted polymer shells of neighboring particles.

Nuclear dynamics in the core-excited state of aqueous ammonia probed by resonant inelastic soft x-ray scattering

2011 ◽  
Vol 84 (10) ◽  
Author(s):  
L. Weinhardt ◽  
M. Weigand ◽  
O. Fuchs ◽  
M. Bär ◽  
M. Blum ◽  
...  
Keyword(s):  
Excited State ◽  
Aqueous Ammonia ◽  
Nuclear Dynamics ◽  
X Ray ◽  
The Core ◽  
X Ray Scattering ◽  
Ray Scattering

Microtubule nucleation sequence studied by time-resolved x-ray scattering and electron microscopy

1983 ◽  
Vol 41 ◽  
pp. 766-767
Author(s):  
Eva-Maria Mandelkow ◽  
Eckhard Mandelkow ◽  
Joan Bordas
Keyword(s):  
Electron Microscopy ◽  
Dynamic Equilibrium ◽  
Time Resolved ◽  
X Ray ◽  
Additional Information ◽  
X Ray Scattering ◽  
Low Concentrations ◽  
Microtubule Growth ◽  
Ray Patterns ◽  
Ray Scattering

When a solution of microtubule protein is changed from non-polymerising to polymerising conditions (e.g. by temperature jump or mixing with GTP) there is a series of structural transitions preceding microtubule growth. These have been detected by time-resolved X-ray scattering using synchrotron radiation, and they may be classified into pre-nucleation and nucleation events. X-ray patterns are good indicators for the average behavior of the particles in solution, but they are difficult to interpret unless additional information on their structure is available. We therefore studied the assembly process by electron microscopy under conditions approaching those of the X-ray experiment. There are two difficulties in the EM approach: One is that the particles important for assembly are usually small and not very regular and therefore tend to be overlooked. Secondly EM specimens require low concentrations which favor disassembly of the particles one wants to observe since there is a dynamic equilibrium between polymers and subunits.

Time-Resolved Cryo-Electron Microscopy of Oscillating Microtubules

1990 ◽  
Vol 48 (1) ◽  
pp. 502-503
Author(s):  
Eva-Maria Mandelkow ◽  
Ron Milligan
Keyword(s):  
Electron Microscopy ◽  
Dynamic Instability ◽  
Entire Solution ◽  
Reaction Scheme ◽  
Time Resolved ◽  
X Ray ◽  
X Ray Scattering ◽  
A Chain ◽  
Ray Scattering

Microtubules form part of the cytoskeleton of eukaryotic cells. They are hollow libers of about 25 nm diameter made up of 13 protofilaments, each of which consists of a chain of heterodimers of α-and β-tubulin. Microtubules can be assembled in vitro at 37°C in the presence of GTP which is hydrolyzed during the reaction, and they are disassembled at 4°C. In contrast to most other polymers microtubules show the behavior of “dynamic instability”, i.e. they can switch between phases of growth and phases of shrinkage, even at an overall steady state [1]. In certain conditions an entire solution can be synchronized, leading to autonomous oscillations in the degree of assembly which can be observed by X-ray scattering (Fig. 1), light scattering, or electron microscopy [2-5]. In addition such solutions are capable of generating spontaneous spatial patterns [6].In an earlier study we have analyzed the structure of microtubules and their cold-induced disassembly by cryo-EM [7]. One result was that disassembly takes place by loss of protofilament fragments (tubulin oligomers) which fray apart at the microtubule ends. We also looked at microtubule oscillations by time-resolved X-ray scattering and proposed a reaction scheme [4] which involves a cyclic interconversion of tubulin, microtubules, and oligomers (Fig. 2). The present study was undertaken to answer two questions: (a) What is the nature of the oscillations as seen by time-resolved cryo-EM? (b) Do microtubules disassemble by fraying protofilament fragments during oscillations at 37°C?

X-ray scattering by 1D molecular Guinier-Preston zones in ordered smectic phases

1992 ◽  
Vol 2 (6) ◽  
pp. 899-913 ◽  
Author(s):  
Patrick Davidson ◽  
Elisabeth Dubois-Violette ◽  
Anne-Marie Levelut ◽  
Brigitte Pansu
Keyword(s):  
X Ray ◽  
X Ray Scattering ◽  
Smectic Phases ◽  
Ray Scattering

An X-ray Scattering Study of Laterally Modulated Structures: Investigation of Coherence and Resolution Effects with a Grating

1996 ◽  
Vol 6 (8) ◽  
pp. 1085-1094 ◽  
Author(s):  
A. Gibaud ◽  
J. Wang ◽  
M. Tolan ◽  
G. Vignaud ◽  
S. K. Sinha
Keyword(s):  
X Ray ◽  
X Ray Scattering ◽  
Modulated Structures ◽  
Scattering Study ◽  
Ray Scattering
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