scholarly journals Crystal structure and vibrational spectra of salts of 1H-pyrazole-1-carboxamidine and its protonation route

2020 ◽  
Author(s):  
Piotr Rejnhardt ◽  
Marek Daszkiewicz
Keyword(s):  
Hydrogen Bonding ◽  
Crystal Structures ◽  
Vibrational Spectra ◽  
Theoretical Calculations ◽  
Equilibrium Constants ◽  
Tautomeric Equilibrium ◽  
Potential Energy Distribution ◽  
Distribution Analysis ◽  
Cationic Form ◽  
Inorganic Acids

Abstract Crystal structures of five salts of 1H-pyrazole-1-carboxamidine, PyCA, with various inorganic acids were determined, (HPyCA)Cl, (HPyCA)Cl·H2O, (HPyCA)Br, (HPyCA)2(I)I3, and (HPyCA)HSO4. Theoretical calculations of the protonation route of PyCA showed that the cationic form present in the studied crystals is energetically privileged. Tautomeric equilibrium constants indicated two isomers as the most stable neutral forms. Calculations for two other tautomers failed resulting in pyrazole and carbodiimid tautomer of cyanamide. Such decomposition is important in a view of guanylation reaction. Hydrogen bonding patterns were studied by means of the graph-set approach. Similarities of the patterns in different crystal structures were demonstrated by the algebraic relations between descriptors of the patterns. The strength of hydrogen bonding network in the crystals was assessed analyzing vibrational spectra. The bands were assigned on the basis of theoretical calculations for the complex [(HPyCA)2Cl4]2– ion and potential energy distribution analysis. The strength of hydrogen bonds was set in the following ascending series (HPyCA)2(I)I3 (4) < (HPyCA)Br (3) < (HPyCA)Cl (1) < (HPyCA)Cl·H2O (2) < (HPyCA)HSO4 (5).

Crystal structures and vibrational spectra of biuret co-crystals with cyanuric and glutaric acids, discussion of hydrogen bonding involving carbonyl groups

2016 ◽  
Vol 231 (5) ◽  
Author(s):  
Irena Matulková ◽  
Jana Mathauserová ◽  
Ivana Císařová ◽  
Ivan Němec ◽  
Jan Fábry
Keyword(s):  
Hydrogen Bonding ◽  
Crystal Structures ◽  
Vibrational Spectra ◽  
Cyanuric Acid ◽  
Carbonyl Groups

AbstractThe title structures of biuret-cyanuric acid (2/2) monohydrate, C

scholarly journals The crystal structures and mechanical properties of the uranyl carbonate minerals roubaultite, fontanite, sharpite, widenmannite, grimselite and čejkaite

2020 ◽  
Vol 7 (21) ◽  
pp. 4197-4221 ◽  
Author(s):  
Francisco Colmenero ◽  
Jakub Plášil ◽  
Jiří Sejkora
Keyword(s):  
Mechanical Properties ◽  
Hydrogen Bonding ◽  
Diffraction Pattern ◽  
Crystal Structures ◽  
First Principles ◽  
X Ray Diffraction ◽  
Carbonate Minerals ◽  
X Ray ◽  
Uranyl Carbonate

The structure, hydrogen bonding, X-ray diffraction pattern and mechanical properties of six important uranyl carbonate minerals, roubaultite, fontanite, sharpite, widenmannite, grimselite and čejkaite, are determined using first principles methods.

Cobalt(II) aldoxime complexes stabilised by halide hydrogen bonding: crystal structures of [Co{HONC(H)(Me)}4X2] (X = Cl or Br) and [Co{HONC(H)(Pr)}4Cl2]

2001 ◽  
pp. 197-201 ◽  
Author(s):  
Jean-Cyrille Hierso ◽  
Elisabeth Bouwman ◽  
Dianne D. Ellis ◽  
Mónica Pérez Cabero ◽  
Jan Reedijk ◽  
...  
Keyword(s):  
Hydrogen Bonding ◽  
Crystal Structures

Supramolecular assembling using synthons with NH—CO(S)—CS—NH and NH—CO—CO—NH functionalities: crystal structures of (S,S)-N,N′-monothiooxalyldileucine methyl ester and its dithio analogue

2004 ◽  
Vol 60 (1) ◽  
pp. 90-96 ◽  
Author(s):  
Biserka Kojić-Prodić ◽  
Berislav Perić ◽  
Zoran Štefanić ◽  
Anton Meden ◽  
Janja Makarević ◽  
...  
Keyword(s):  
Hydrogen Bond ◽  
Hydrogen Bonding ◽  
Methyl Ester ◽  
Crystal Structures ◽  
Hydrogen Bond Network ◽  
Asymmetric Unit ◽  
Orthorhombic Space Group ◽  
Space Group ◽  
Bond Network ◽  
Bonding Systems

To compare the structural properties of oxalamide and thiooxalamide groups in the formation of hydrogen bonds suitable for supramolecular assemblies a series of retropeptides was studied. Some of them, having oxalamide bridges, are gelators of organic solvents and water. However, retropeptides with oxygen replaced by the sp 2 sulfur have not exhibited such properties. The crystal structures of the two title compounds are homostructural, i.e. they have similar packing arrangements. The monothio compound crystallizes in the orthorhombic space group P212121 with two molecules in the asymmetric unit arranged in a hydrogen-bond network with an approximate 41 axis along the crystallographic b axis. However, the dithio and dioxo analogues crystallize in the tetragonal space group P41 with similar packing patterns and hydrogen-bonding systems arranged in agreement with a crystallographic 41 axis. Thus, these two analogues are isostructural having closely related hydrogen-bonding patterns in spite of the different size and polarity of oxygen and sulfur which serve as the proton acceptors.

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