scholarly journals Relationship between the Crystal Structure and Tuberculostatic Activity of Some 2-Amidinothiosemicarbazone Derivatives of Pyridine

Materials ◽  
2022 ◽  
Vol 15 (1) ◽  
pp. 349
Author(s):  
Katarzyna Gobis ◽  
Małgorzata Szczesio ◽  
Andrzej Olczak ◽  
Tomasz Pawlak ◽  
Ewa Augustynowicz-Kopeć ◽  
...  

Tuberculosis remains one of the most common diseases affecting developing countries due to difficult living conditions, the rapidly increasing resistance of M. tuberculosis strains and the small number of effective anti-tuberculosis drugs. This study concerns the relationship between molecular structure observed in a solid-state by X-ray diffraction and the 15N NMR of a group of pyridine derivatives, from which promising activity against M. tuberculosis was reported earlier. It was found that the compounds exist in two tautomeric forms: neutral and zwitterionic. The latter form forced the molecules to adopt a stable, unique, flat frame due to conjugation and the intramolecular hydrogen bond system. As the compounds exist in a zwitterionic form in the crystal state generally showing higher activity against tuberculosis, it may indicate that this geometry of molecules is the “active” form.

1991 ◽  
Vol 56 (4) ◽  
pp. 880-885 ◽  
Author(s):  
Oľga Hritzová ◽  
Dušan Koščík

Intramolecular hydrogen bonds of the N-H···O=C type have been detected in the derivatives of N-substituted N’-benzoyl- and N’-(2-chlorobenzoyl)thiourea on the basis of IR spectral studies. The title compounds can exist in two tautomeric forms.


Author(s):  
Yuliya V. Butina ◽  
Elena A. Danilova ◽  
Maxim V. Dmitriev ◽  
Aleksey V. Solomonov

For citation:Butina Yu.V., Danilova E.A., Dmitriev M.V., Solomonov А.V. Crystal structure of bis[1-(diaminomethylene)-thiouron-1-ium] sulfate. Izv. Vyssh. Uchebn. Zaved. Khim. Khim. Tekhnol. 2017. V. 60. N 1. P. 45-49. In this work crystal data of bis[1-(diaminomethylene)-thiouron-1-ium] sulfate is shown. This compound was characterized by IR spectroscopy and elemental analysis. The monocrystal of this compound was obtained and the structure was confirmed by single X-ray analysis. Moreover, the work describes potential application of synthesized compound. Comparative characteristics of thiourea and its known salts are demonstrated. It is known, that derivatives of thiourea have several tautomeric forms, which can be different in crystalline state or in solution. Therefore, changed scheme of the synthesis of 2-imino-4-thiobiuret is proposed. Elemental cell of crystal consists of two 1-(diaminomethylene)thiouron-1-ium cations and one sulfat anion. A full set of X-ray diffraction data was deposited in the Cambridge Structural Database (deposit CCDC 1421710) and it can be gotten from the site www.ccdc.cam.ac.uk/data_request/cif.


1996 ◽  
Vol 61 (9) ◽  
pp. 1295-1306 ◽  
Author(s):  
Zdeněk Mička ◽  
Lucie Prokopová ◽  
Ivana Císařová ◽  
David Havlíček

Magnesium selenates double salts K2Mg(SeO4)2.6H2O, Rb2Mg(SeO4)2.6H2O, Cs2Mg(SeO4)2.6H2O, and (NH4)2Mg(SeO4)2.6H2O have been studied by means of X-ray diffraction methods, thermoanalytical methods, and infrared spectroscopy. The basic building units of these compounds are slightly deformed tetrahedra of selenate anions and octahedra of hexaaquamagnesium(II) cations interconnected by a system of hydrogen bonds. The investigation of IR spectra has been used in the discussion of X-ray diffraction results in the field of description of the hydrogen bond system and deformation of the basic polyhedra of selenate anion and hexaaquamagnesium cation. The thermoanalytical studies are used in evaluating the effects of hydrogen bonds and polarization influence of M+ cations on thermal stability of the compounds studied.


2007 ◽  
Vol 63 (2) ◽  
pp. 303-308 ◽  
Author(s):  
Andrew Parkin ◽  
Martin Adam ◽  
Richard I. Cooper ◽  
Derek S. Middlemiss ◽  
Chick C. Wilson

A new polymorph of 2,4-dihydroxybenzoic acid is reported. The structure was characterized by multiple-temperature X-ray diffraction and solid-state DFT computations. The material shows a geometric pattern of hydrogen bonding consistent with cooperativity between the intermolecular carboxylic acid dimer and intramolecular hydrogen bonds. The presence of proton disorder within this hydrogen-bond system, which would support such a cooperative model, was not fully ruled out by the initial X-ray studies. However, solid-state calculations on the three possible end-point tautomers indicate that the dominant crystallographically observed configuration is substantially lower in energy than the other tautomers (by at least 9 kJ mol−1), indicating that no disorder should be expected. It is therefore concluded that no disorder is observed either in the intra- or intermolecular hydrogen bonds of the title compound and that the cooperativity between the hydrogen bonds is not present within the temperature range studied.


Molecules ◽  
2021 ◽  
Vol 26 (23) ◽  
pp. 7297
Author(s):  
Sergey A. Anufriev ◽  
Akim V. Shmal’ko ◽  
Kyrill Yu. Suponitsky ◽  
Igor B. Sivaev

A simple and efficient method was developed for the one-pot synthesis of 3-aryl derivatives of ortho-carborane with sensitive functional groups using 3-iodo-ortho-carborane and aryl zinc bromides that were generated in situ. A series of 3-aryl-ortho-carboranes, including those containing nitrile and ester groups, 3-RC6H4-1,2-C2B10H11 (R = p-Me, p-NMe2, p-OCH2OMe, p-OMe, o-CN, p-CN, o-COOEt, m-COOEt, p-COOEt) was synthesized using this approach. The solid-state structures of 3-RC6H4-1,2-C2B10H11 (R = p-OMe, o-CN, and p-CN) were determined by single crystal X-ray diffraction. The intramolecular hydrogen bonding involving the ortho-substituents of the aryl ring and the CH and BH groups of carborane was discussed.


2015 ◽  
Vol 79 (1) ◽  
pp. 11-24 ◽  
Author(s):  
G. Ventruti ◽  
G. Della Ventura ◽  
R. Orlando ◽  
F. Scordari

AbstractThe crystal structure of hohmannite, Fe3+2[O(SO4)2]·8H2O, was studied by means of single-crystal X-ray diffraction (XRD) and vibrational spectroscopy. The previous structural model was confirmed, though new diffraction data allowed the hydrogen-bond system to be described in greater and more accurate detail.Ab initiocalculations were performed in order to determine accurate H positions and to support the experimental model obtained from XRD data. Infrared and Raman spectra are presented for the first time for this compound and comments are made on the basis of the crystal structure and the known literature for sulfate minerals.


2016 ◽  
Vol 12 (8) ◽  
pp. 295-300
Author(s):  
Olga Kovalchukova ◽  
Amangdam A.T. ◽  
Strashnova S.B. ◽  
Strashnov P.V. ◽  
Romashkina E.P. ◽  
...  

Using spectrophotometric titration technique, the processes of complex formation of some phenylazo-derivatives of methylphloroglucinol (MPG) containing hydroxo-, nitro- and nitroso-substituents were studied. The spectral criteria of neutral and ionized forms of the organic ligands in their different tautomeric forms were determined.It was detected that the complex formation is accompanied by formation of one or two chelate cycles which involve azo- or nitroso-fragments and neighboring OH-groups of the organic ligands. Different types of coordination lead to different changes in the electronic absorption spectra.The DFT-B3LYP modeling of a Ni(II) complex of α-hydroxyphenylazo MPG established the most probable coordination mode of the organic ligand: tridentate chelating dianion, distorted square coordination of Ni-cations including one water molecule.  The theoretical results are in a good accordance with the experimental data.


1983 ◽  
Vol 48 (2) ◽  
pp. 586-595 ◽  
Author(s):  
Alexander Perjéssy ◽  
Pavol Hrnčiar ◽  
Ján Šraga

The wave numbers of the fundamental C=O and C=C stretching vibrations, as well as that of the first overtone of C=O stretching vibration of 2-(3-, and 4-substituted phenylmethylene)-1,3-cycloheptanediones and 1,3-cycloheptanedione were measured in tetrachloromethane and chloroform. The spectral data were correlated with σ+ constants of substituents attached to phenyl group and with wave number shifts of the C=O stretching vibration of substituted acetophenones. The slope of the linear dependence ν vs ν+ of the C=C stretching vibration of the ethylenic group was found to be more than two times higher than that of the analogous correlation of the C=O stretching vibration. Positive values of anharmonicity for asymmetric C=O stretching vibration can be considered as an evidence of the vibrational coupling in a cyclic 1,3-dicarbonyl system similarly, as with derivatives of 1,3-indanedione. The relationship between the wave numbers of the symmetric and asymmetric C=O stretching vibrations indicates that the effect of structure upon both vibrations is symmetric. The vibrational coupling in 1,3-cycloheptanediones and the application of Seth-Paul-Van-Duyse equation is discussed in relation to analogous results obtained for other cyclic 1,3-dicarbonyl compounds.


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