scholarly journals Ultrashort Hδ+ ··· Hδ- intermolecular distance in a supramolecular system in the solid state

2021 ◽  
Author(s):  
Alfonso Garcia-Marquez ◽  
Antonio Frontera ◽  
Thierry Roisnel ◽  
Rafael Gramage-Doria
Keyword(s):  
Solid State ◽  
Supramolecular System ◽  
Intermolecular Distance ◽  
Hydrogen Atoms ◽  
Covalent Interaction

Herein we report experimental evidences for the shortest intermolecular distance reported for two electronically-different hydrogen atoms in the solid state. The Hδ+ ··· Hδ- non-covalent interaction was studied by theoretical...

Infrared spectra of KH2F3 and the structure of the H2F3− ion

1967 ◽  
Vol 45 (12) ◽  
pp. 1347-1350 ◽  
Author(s):  
A. Ažman ◽  
A. Ocvirk ◽  
D. Hadži ◽  
Paul A. Giguère ◽  
Michel Schneider
Keyword(s):  
Solid State ◽  
Infrared Spectra ◽  
Infrared Absorption ◽  
Normal Coordinate Analysis ◽  
Force Constants ◽  
Hydrogen Atoms ◽  
Normal Coordinate ◽  
Bending Modes

The infrared absorption of KH2F3 and KD2F3in the solid state was measured between 4 000 and 200 cm−1 The observed bands can be assigned to the stretching and bending modes of the bent H2F3− ion. A normal coordinate analysis was carried out to determine the Urey–Bradley force constants. The results suggest that the hydrogen atoms are not exactly halfway between two fluorine atoms, contrary to the case of the HF2− ion.Les spectres infrarouges de KH2F3 et KD2F3 à l'état solide ont été mesurés entre 4 000 et 200 cm−1 afin d'identifier les vibrations fondamentales de l'anion H2F3−. Les constantes de forces de rappel selon le modèle de Urey–Bradley ont pu être déterminées par analyse des coordonnées normales. Les résultats indiquent que les atomes d'hydrogène ne sont pas exactement à mi-chemin entre deux atomes de fluor, contrairement au cas de l'ion HF2−.

Measurement and calculation of 13C chemical shift tensors in α-glucose and α-glucose monohydrate

2011 ◽  
Vol 89 (7) ◽  
pp. 737-744 ◽  
Author(s):  
Darren H. Brouwer ◽  
Kevin P. Langendoen ◽  
Quentin Ferrant
Keyword(s):  
Solid State ◽  
Chemical Shift ◽  
Quantum Chemical ◽  
Density Functional ◽  
Chemical Shifts ◽  
Chemical Calculation ◽  
Hydrogen Atoms ◽  
Chemical Shift Tensors ◽  
Experimental Values ◽  
Crystalline Forms

The 13C chemical shift tensors of two crystalline forms of glucose (α-glucose and α-glucose·H2O) were determined from one-dimensional (1D) and two-dimensional (2D) solid-state nuclear magnetic resonance (NMR) spectroscopy experiments. The experimental values determined from 1D and 2D methods are in very good agreement. Quantum chemical calculations were also carried out using the gauge-including projector augmented wave (GIPAW) method for plane-wave density functional theory (DFT) as implemented in the CAmbridge Serial Total Energy Package (CASTEP). The calculated 13C chemical shifts were found to be in excellent agreement with experimental values for crystal structures that had their hydrogen atoms optimized and after an appropriate calibration was applied to convert calculated chemical shieldings into chemical shifts. The work presented here lays an important foundation for future solid-state NMR and quantum chemical calculation investigations of the various crystalline forms of cellulose.

Structure and conformation of the anticodon nucleoside 5-methoxyuridine in the solid state and in solution

1983 ◽  
Vol 61 (10) ◽  
pp. 2299-2304 ◽  
Author(s):  
George I. Birnbaum ◽  
Wayne J. P. Blonski ◽  
Frank E. Hruska
Keyword(s):  
Solid State ◽  
Three Dimensional ◽  
Direct Methods ◽  
Pyrimidine Ring ◽  
Dimensional Structure ◽  
Side Chain ◽  
Monoclinic Space Group ◽  
Hydrogen Atoms ◽  
Cell Dimensions ◽  
Enol Tautomer

The three-dimensional structure of 5-methoxyuridine (mo5U) was determined with much higher precision than in a previous study (Hillen etal. J. Carbohydr. Nucleosides Nucleotides, 5, 23 (1978)). The crystals belong to the monoclinic space group P21 and the cell dimensions are a = 8.916(2), b = 14.372(2), c = 4.714(1) Å, β = 97.44(2)°. Intensity data were measured with a diffractometer and the structure was solved by direct methods. Least-squares refinement, which included all hydrogen atoms, converged at R = 0.031. The conformation about the glycosyl bond is anti (χCN = 23.1°), the pucker of the ribose ring is C(3′)endo, and the conformation of the —CH2OH side chain is gauche+. A comparison of the bond lengths N(3)—C(4) and C(4)—O(4) with those in uridine does not support the conclusion of Hillen etal. about a shift to the enol tautomer in mo5U. However, there are other changes in the geometry of the pyrimidine ring due to substitution at C(5). A conformational analysis, based on 1H and 13C nmr data, shows that the preferred conformation in solution is that observed in the solid state.

Pyrimidopteridine N ‐Oxide Organic Photoredox Catalysts: Characterization, Application and Non‐Covalent Interaction in Solid State

2019 ◽  
Vol 25 (17) ◽  
pp. 4325-4329 ◽  
Author(s):  
Richy Hauptmann ◽  
Andranik Petrosyan ◽  
Franziska Fennel ◽  
Miguel A. Argüello Cordero ◽  
Annette‐E. Surkus ◽  
...  
Keyword(s):  
Solid State ◽  
Covalent Interaction

1,3,5-Tri(iodoethynyl)-2,4,6-trifluorobenzene: halogen-bonded frameworks and NMR spectroscopic analysis

2017 ◽  
Vol 73 (2) ◽  
pp. 153-162 ◽  
Author(s):  
Patrick M. J. Szell ◽  
Bulat Gabidullin ◽  
David L. Bryce
Keyword(s):  
Solid State ◽  
Crystal Engineering ◽  
Halogen Bond ◽  
Halogen Bonding ◽  
Lewis Base ◽  
Phosphonium Salts ◽  
Covalent Interaction ◽  
Framework Materials ◽  
Engineering Strategy ◽  
Triphenylphosphonium Bromide

Halogen bonding is the non-covalent interaction between the region of positive electrostatic potential associated with a covalently bonded halogen atom, named the σ-hole, and a Lewis base. Single-crystal X-ray diffraction structures are reported for a series of seven halogen-bonded cocrystals featuring 1,3,5-tris(iodoethynyl)-2,4,6-trifluorobenzene (1) as the halogen-bond donor, and bromide ions (as ammonium or phosphonium salts) as the halogen-bond acceptors: (1)·MePh3PBr, (1)·EtPh3PBr, (1)·acetonyl-Ph3PBr, (1)·Ph4PBr, (1)·[bis(4-fluorophenyl)methyl]triphenylphosphonium bromide, and two new polymorphs of (1)·Et3BuNBr. The cocrystals all feature moderately strong iodine–bromide halogen bonds. The crystal structure of pure [bis(4-fluorophenyl)methyl]triphenylphosphonium bromide is also reported. The results of a crystal engineering strategy of varying the size of the counter-cation are explored, and the features of the resulting framework materials are discussed. Given the potential utility of (1) in future crystal engineering applications, detailed NMR analyses (in solution and in the solid state) of this halogen-bond donor are also presented. In solution, complex13C and19F multiplets are explained by considering the delicate interplay between variousJcouplings and subtle isotope shifts. In the solid state, the formation of (1)·Et3BuNBr is shown through significant13C chemical shift changes relative to pure solid 1,3,5-tris(iodoethynyl)-2,4,6-trifluorobenzene.

Ergosterol Increases the Intermolecular Distance of Amphotericin B in the Membrane-Bound Assembly As Evidenced by Solid-State NMR†

Biochemistry ◽  
2008 ◽  
Vol 47 (51) ◽  
pp. 13463-13469 ◽  
Author(s):  
Yuichi Umegawa ◽  
Nobuaki Matsumori ◽  
Tohru Oishi ◽  
Michio Murata
Keyword(s):  
Solid State ◽  
Amphotericin B ◽  
Solid State Nmr ◽  
Intermolecular Distance ◽  
Membrane Bound

The Combined Inelastic Neutron Scattering (INS) and Solid-State DFT Study of Hydrogen-Atoms Dynamics in Kaolinite-Dimethylsulfoxide Intercalate

2010 ◽  
Vol 58 (1) ◽  
pp. 52-61 ◽  
Author(s):  
L'ubomír Smrčok ◽  
Daniel Tunega ◽  
Anibal Javier Ramirez-Cuesta ◽  
Alexander Ivanov ◽  
Jana Valúchová
Keyword(s):  
Solid State ◽  
Neutron Scattering ◽  
Inelastic Neutron Scattering ◽  
Inelastic Neutron ◽  
Dft Study ◽  
Hydrogen Atoms
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