Factors Governing the Three-Dimensional Hydrogen Bond Network Structure of Poly(m-phenylene isophthalamide) and a Series of Its Model Compounds:  (1) Systematic Classification of Structures Analyzed by the X-ray Diffraction Method

2002 ◽  
Vol 106 (27) ◽  
pp. 6842-6848 ◽  
Author(s):  
Piyarat Nimmanpipug ◽  
Kohji Tashiro ◽  
Yasuhiko Maeda ◽  
Orapin Rangsiman
Keyword(s):  
Hydrogen Bond ◽  
Three Dimensional ◽  
Diffraction Method ◽  
Hydrogen Bond Network ◽  
X Ray Diffraction ◽  
Model Compounds ◽  
Systematic Classification ◽  
X Ray ◽  
Bond Network

scholarly journals Effect of pressure on a mixed valence FeiiFeiii2complex

2014 ◽  
Vol 70 (a1) ◽  
pp. C901-C901
Author(s):  
Solveig Madsen ◽  
Jacob Overgaard ◽  
Bo Iversen
Keyword(s):  
Phase Transition ◽  
Hydrogen Bond ◽  
Mixed Valence ◽  
Hydrogen Bond Network ◽  
X Ray Diffraction ◽  
X Ray ◽  
Effect Of Pressure ◽  
Bond Network ◽  
Fe Sites ◽  
Cyano Groups

Intramolecular electron transfer (ET) in mixed valence (MV) oxo-centered [FeiiFeiii2O(carboxylate)6(ligand)3]·solvent complexes is highly dependent on temperature, on the nature of the ligands, and on the presence of crystal solvent molecules [1]. Whereas the effects of temperature, crystal solvent, and ligand variation on the details of the ET have been explored thoroughly, the effect of pressure is less well described [2]. The effect of pressure on the ET in MV Fe3O(cyanoacetate)6(water)3has been investigated with single crystal X-ray diffraction and Mössbauer spectroscopy. Previous multi-temperature studies have shown that at room temperature the ET between the three Fe sites is fast and the observed structure of the Fe3core is a perfectly equilateral triangle [3]. Cooling the complex below 130 K induces a phase transition as the ET slows down. Below 120 K the Fe3core is distorted due to the localization of the itinerant electron on one of the three Fe sites in the triangle (the complex is then in the valence trapped state). The valence trapping is complete within a temperature interval of just 10 K. The abruptness of the transition has been attributed to the extended hydrogen bond network involving water ligands and cyano groups, promoting intermolecular cooperative effects. The high-pressure X-ray diffraction data show that there is a 900flip of half the cyano groups at 3.5 GPa, which dramatically changes the hydrogen bond network. At a slightly higher pressure, a phase transition is found to occur. The five single crystals investigated all broke into minor fragments at the transition; however triclinic unit cells, similar to the low temperature unit cell, could be indexed from selected spots. Additional evidence that the complex is valence trapped comes from high pressure Mössbauer spectra measured above the phase transition (4 GPa). The relationship between valence trapping and the structural changes will in this work be highlighted using void space and Hirshfeld surface analysis.

Unraveling the Hydrogen Bond Network in a Theophylline–Pyridoxine Salt Cocrystal by a Combined X-ray Diffraction, Solid-State NMR, and Computational Approach

2018 ◽  
Vol 18 (4) ◽  
pp. 2225-2233 ◽  
Author(s):  
Federica Rossi ◽  
Paolo Cerreia Vioglio ◽  
Simone Bordignon ◽  
Valeria Giorgio ◽  
Carlo Nervi ◽  
...  
Keyword(s):  
Hydrogen Bond ◽  
Solid State ◽  
Solid State Nmr ◽  
Computational Approach ◽  
Hydrogen Bond Network ◽  
X Ray Diffraction ◽  
X Ray ◽  
Bond Network

scholarly journals Revealing hydrogen atoms in a highly-absorbing material: an X-ray diffraction study and Torque method calculations for lead-uranyl-oxide mineral curite

RSC Advances ◽  
2019 ◽  
Vol 9 (18) ◽  
pp. 10058-10063 ◽  
Author(s):  
Seyedayat Ghazisaeed ◽  
Boris Kiefer ◽  
Jakub Plášil
Keyword(s):  
Crystal Structure ◽  
Hydrogen Bond ◽  
Diffraction Study ◽  
Hydrogen Bond Network ◽  
X Ray Diffraction ◽  
Hydrogen Atoms ◽  
X Ray ◽  
Oxide Mineral ◽  
Absorbing Material ◽  
Bond Network

The complete crystal structure, including the hydrogen bond network, of lead uranyl-oxide mineral curite, ideally Pb3(H2O)2[(UO2)4O4(OH)3]2, was resolved by combining single-crystal X-ray diffraction and theory.

X-Ray Diffraction Study of Cs5(HSO4)3(H2PO4)2, a New Solid Acid with a Unique Hydrogen-Bond Network

1998 ◽  
Vol 140 (2) ◽  
pp. 251-265 ◽  
Author(s):  
Sossina M. Haile ◽  
Pamela M. Calkins
Keyword(s):  
Hydrogen Bond ◽  
Diffraction Study ◽  
Solid Acid ◽  
Hydrogen Bond Network ◽  
X Ray Diffraction ◽  
X Ray ◽  
Bond Network

(NH4)[B3PO6(OH)3]·0.5H2O

2007 ◽  
Vol 63 (11) ◽  
pp. i185-i185 ◽  
Author(s):  
Wei Liu ◽  
Jingtai Zhao
Keyword(s):  
Crystal Structure ◽  
Hydrogen Bond ◽  
Three Dimensional ◽  
Dimensional Structure ◽  
Water Molecules ◽  
Hydrogen Bond Network ◽  
Ammonium Ions ◽  
One Dimensional ◽  
Bond Network ◽  
Solvothermal Conditions

The title compound, ammonium catena-[monoboro-monodihydrogendiborate-monohydrogenphosphate] hemihydrate, was obtained under solvothermal conditions using glycol as the solvent. The crystal structure is constructed of one-dimensional infinite borophosphate chains, which are interconnected by ammonium ions and water molecules via a complex hydrogen-bond network to form a three-dimensional structure. The water molecules of crystallization are disordered over inversion centres, and their H atoms were not located.

X-ray Absorption Spectroscopy Study of the Hydrogen Bond Network in the Bulk Water of Aqueous Solutions

2005 ◽  
Vol 109 (27) ◽  
pp. 5995-6002 ◽  
Author(s):  
Lars-Åke Näslund ◽  
David C. Edwards ◽  
Philippe Wernet ◽  
Uwe Bergmann ◽  
Hirohito Ogasawara ◽  
...  
Keyword(s):  
Hydrogen Bond ◽  
Aqueous Solutions ◽  
Absorption Spectroscopy ◽  
Bulk Water ◽  
Hydrogen Bond Network ◽  
Spectroscopy Study ◽  
X Ray ◽  
Bond Network ◽  
X Ray Absorption

scholarly journals X-ray structures of catalytic intermediates of cytochrome c oxidase provide insights into its O2 activation and unidirectional proton-pump mechanisms

2020 ◽  
Vol 295 (17) ◽  
pp. 5818-5833
Author(s):  
Atsuhiro Shimada ◽  
Yuki Etoh ◽  
Rika Kitoh-Fujisawa ◽  
Ai Sasaki ◽  
Kyoko Shinzawa-Itoh ◽  
...  
Keyword(s):  
Hydrogen Bond ◽  
Resonance Raman Spectroscopy ◽  
Transmembrane Helix ◽  
Water Channel ◽  
Bound State ◽  
Proton Pumping ◽  
Hydrogen Bond Network ◽  
X Ray ◽  
Catalytic Intermediates ◽  
Bond Network

Cytochrome c oxidase (CcO) reduces O2 to water, coupled with a proton-pumping process. The structure of the O2-reduction site of CcO contains two reducing equivalents, Fea32+ and CuB1+, and suggests that a peroxide-bound state (Fea33+–O−–O−–CuB2+) rather than an O2-bound state (Fea32+–O2) is the initial catalytic intermediate. Unexpectedly, however, resonance Raman spectroscopy results have shown that the initial intermediate is Fea32+–O2, whereas Fea33+–O−–O−–CuB2+ is undetectable. Based on X-ray structures of static noncatalytic CcO forms and mutation analyses for bovine CcO, a proton-pumping mechanism has been proposed. It involves a proton-conducting pathway (the H-pathway) comprising a tandem hydrogen-bond network and a water channel located between the N- and P-side surfaces. However, a system for unidirectional proton-transport has not been experimentally identified. Here, an essentially identical X-ray structure for the two catalytic intermediates (P and F) of bovine CcO was determined at 1.8 Å resolution. A 1.70 Å Fe–O distance of the ferryl center could best be described as Fea34+ = O2−, not as Fea34+–OH−. The distance suggests an ∼800-cm−1 Raman stretching band. We found an interstitial water molecule that could trigger a rapid proton-coupled electron transfer from tyrosine-OH to the slowly forming Fea33+–O−–O−–CuB2+ state, preventing its detection, consistent with the unexpected Raman results. The H-pathway structures of both intermediates indicated that during proton-pumping from the hydrogen-bond network to the P-side, a transmembrane helix closes the water channel connecting the N-side with the hydrogen-bond network, facilitating unidirectional proton-pumping during the P-to-F transition.

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