Proton tautomerism and stereoisomerism in 5-[(dimethylamino)methylidene]-4-[3/4-(trifluoromethylphenyl)amino]-1,3-thiazol-2(5H)-ones: synthesis, crystal structure and spectroscopic studies
5-[(Dimethylamino)methylidene]-4-{[3-(trifluoromethyl)phenyl]amino}-1,3-thiazol-2(5H)-one and the [4-(trifluoromethyl)phenyl]amino derivative, both C13H12F3N3OS, with the trifluoromethyl group substituted at the arene ring at the meta and para positions, were synthesized to study the structural changes associated with proton tautomerism of the amidine system. The studied compounds were found to be in the amine tautomeric form in both the solid and the liquid (dimethyl sulfoxide solutions) phase. In both isomers, the [(trifluoromethyl)phenyl]amino residue assumes a synperiplanar conformation with respect to the thiazolone s...
Source: Acta Crystallographica Section C - October 24, 2023 Category: Chemistry Authors: Pyrih, A. Ł api ń ski, A. Zi ę ba, S. Mizera, A. Lesyk, R. Gzella, A.K. Jaskolski, M. Tags: thiazolidinone proton tautomerism stereoisomerism X-ray analysis crystal structure NMR spectroscopy DFT calculations research papers Source Type: research
Crystallographic, spectroscopic and thermal studies of 1-(4-bromophenyl)-5-(2,5-dimethyl-1H-pyrrol-1-yl)-3-methyl-1H-pyrazole
The new title pyrrole – pyrazole derivative, C16H16BrN3, was synthesized through a citric acid-catalyzed Paal – Knorr reaction between acetonylacetone and 1-(4-bromophenyl)-3-methyl-1H-pyrazol-5-amine under mild reaction conditions. This synthetic protocol is noteworthy for its utilization of stoichiometric amounts of the reactants, an ecofriendly solvent and a cost-effective, non-toxic and biodegradable organocatalyst. A comprehensive understanding of the molecular structure was gained through spectroscopic, thermal and X-ray crystallographic analyses. The crystal structure is characterized by weak interactions, where...
Source: Acta Crystallographica Section C - October 24, 2023 Category: Chemistry Authors: Moreno-Su á rez, E. Avila-Acosta, R. S á nchez-Ram í rez, K. Castillo, J.-C. Mac í as, M.A. Tags: 5-aminopyrazole homogeneous catalysis citric acid pyrrole X-ray crystallography crystal structure Hirshfeld surface map weak interactions Paal – Knorr reaction research papers Source Type: research
Mythical compounds
(Source: Acta Crystallographica Section C)
Source: Acta Crystallographica Section C - October 24, 2023 Category: Chemistry Authors: Fanwick, P.E. Tags: crystallographic errors atom misassignments incorrect modeling disordered guest molecules incorrect space group incorrect cell size checkCIF scientific commentaries Source Type: research
Perovskite-related structures of Ba2YAlO5 and the β and α phases of Ba6Y2Al4O15 containing AlO4 tetrahedra
Single crystals of Ba2YAlO5 and of the α and β phases of Ba6Y2Al4O15 suitable for X-ray structure analysis were obtained via grain growth of polycrystalline samples prepared by solid-state reactions. Ba2YAlO5 was found to have a monoclinic crystal structure, with lattice parameters a = 7.2333 (7), b = 6.0254 (5), c = 7.4294 (7) Å and β = 117.249 (3) ° , and to belong to the space group P21/m, while α -Ba6Y2Al4O15 was determined to be monoclinic, with a = 5.9019 (2), b = 7.8744 (3), c = 9.6538 (3) Å and β = 107.7940 (10) ° , and the space group Pm, and...
Source: Acta Crystallographica Section C - October 17, 2023 Category: Chemistry Authors: Simura, R. Suzuki, Y. Yamane, H. Tags: aluminate crystal structure perovskite-type structure oxygen-coordinated tetrahedron octahedron research papers Source Type: research
Crystal structure and synthesis of the bis(anthracene)dicuprate dianion as the dipotassium salt, [K(tetrahydrofuran)2]2[{Cu(9,10- η 2-anthracene)}2], the first anionic arene complex of copper
Reactions of (tricyclohexylphosphane)copper(I) chloride with two equivalents of potassium anthracene (KAn) in tetrahydrofuran (THF) at 200 K provides air-sensitive but thermally stable (at 293 K) solutions from which yellow crystalline blocks of bis[bis(tetrahydrofuran- κ O)potassium] bis( μ -anthracene- κ 2C9:C10)dicopper, [K(THF)2]2[{Cu(9,10- η 2-C14H10)}2] or [K(C4H8O)2]2[Cu2(C14H10)2], 1, were isolated in about 50% yield. Single-crystal X-ray crystallographic analysis of 1 confirmed the presence of the first known (arene)cuprate. Also, unlike all previously known homoleptic (anthracene)metallates of d-block...
Source: Acta Crystallographica Section C - October 3, 2023 Category: Chemistry Authors: Young, V.G. Brennessel, W.W. Ellis, J.E. Tags: anthracene copper arenecuprate crystal structure tetrahydrofuran research papers Source Type: research
Supramolecular interactions in some organic hydrated 2,4,6-triaminopyrimidinium carboxylate and sulfate salts
Four salts, namely, 2,4,6-triaminopyrimidinium 6-chloronicotinate dihydrate, C4H8N5+ · C6H3ClNO2 − · 2H2O, (I), 2,4,6-triaminopyrimidinediium pyridine-2,6-dicarboxylate dihydrate, C4H9N52+ · C7H3NO42 − · 2H2O, (II), 2,4,6-triaminopyrimidinediium sulfate monohydrate, C4H9N52+ · SO42 − · H2O, (III), and 2,4,6-triaminopyrimidinium 3,5-dinitrobenzoate dihydrate, C4H8N5+ · C7H3N2O6 − · 2H2O, (IV), were synthesized and characterized by X-ray diffraction techniques. Proton transfer from the corresponding acid to the pyrimidine base has occurred in all four crystal structures. Of the four salts, two [(I) and (IV)] ...
Source: Acta Crystallographica Section C - September 25, 2023 Category: Chemistry Authors: Sangavi, M. Kumaraguru, N. McMillen, C.D. Butcher, R.J. Tags: pyrimidine base monoprotonated base diprotonated base ring motif hydration of nucleobases crystal structure research papers Source Type: research
Pressure-induced metallization in the absence of a structural transition in the layered transition-metal dichalcogenide ZrSe2
First-principles calculations were carried out on the ZrSe2 compound, which has been of interest owing to its technologically important physical properties. The structural, electronic and optical properties of this compound were investigated under pressure through the plane wave pseudopotential approach within the framework of density functional theory. A comparison between the computed crystal structure parameters and the corresponding experimental counterparts shows a very good agreement between them. Fitting the pressure – volume data using the third-order Birch – Murnaghan equation of state yielded a bulk modulus B...
Source: Acta Crystallographica Section C - September 22, 2023 Category: Chemistry Authors: Xiao, L.-P. Yi, X.-J. Tags: high pressure electronic structure metallization ab initio calculations structural transition dichalcogenide zirconium selenide research papers Source Type: research
Synthesis, structures and properties of two donor – acceptor acridone-based compounds
Two donor – acceptor acridone-based compounds, namely, 2-{10-[4-(diphenylamino)phenyl]acridin-9-ylidene}malononitrile (TPA-AD-DCN), C34H22N4, and 2-{10-[4-(9H-carbazol-9-yl)phenyl]acridin-9-ylidene}malononitrile (CzPh-AD-DCN), C34H20N4, have been synthesized in high yield and their structures determined. TPA-AD-DCN and CzPh-AD-DCN crystallized in the centrosymmetric space groups P\overline{1} and P21/c, respectively. Both molecules adopt a `butterfly-like' configuration of the common part of the structure and differences occur within the substituents on the acridine N atom. A Hirshfeld surface analysis showed that the H....
Source: Acta Crystallographica Section C - September 21, 2023 Category: Chemistry Authors: Chen, Z. Xin, G. Gao, P. Jin, Y. Tags: crystal structure donor-acceptor acridone-based Ullmann amination Knoevenagel condensation butterfly-like configuration C[triple-bond]N... π interactions Hirshfeld surface analysis crystallization-induced emission research papers Source Type: research
Two new bismuth salts with succinic acid: synthesis, structural, spectroscopic and thermal characterization
Two novel bismuth succinate hydrates, namely, poly[[diaqua( μ 3-butane-1,4-dicarboxylato)hemi( μ -butane-1,4-dicarboxylato)bismuth] monohydrate], {[Bi(C4H4O4)1.5(H2O)2] · H2O}n (1), and poly[[ μ -aqua-aqua( μ 3-butane-1,4-dicarboxylato)( μ -butane-1,4-dicarboxylato)- μ -oxido-dibismuth] monohydrate], {[Bi2(C4H4O4)2O(H2O)2] · H2O}n (2), have been synthesized. Their crystal structures were determined by single-crystal X-ray diffraction and the compounds were characterized by IR and Raman spectroscopy, powder X-ray diffraction and thermal analysis. The crystal structure analysis revealed that the compounds are coordin...
Source: Acta Crystallographica Section C - September 21, 2023 Category: Chemistry Authors: Timakova, E.V. Afonina, L.I. Drebushchak, T.N. Zakharov, B.A. Tags: bismuth compound crystal structure succinic acid active pharmaceutical ingredient API IR spectroscopy Raman spectroscopy thermal analysis research papers Source Type: research
X-ray-determined structure of the technetium complex [Tc2( μ -CO)2(NC5H5)2(CO)6] revisited: [Tc2( μ -OMe)2(NC5H5)2(CO)6] as the correct formulation
Some of us reported previously the structure of di- μ -carbonyl-bis[tricarbonyl(pyridine)technetium], [Tc2( μ -CO)2(C5H5N)2(CO)6], as the main product of the reaction of [Tc2(CO)10] with pyridine at room temperature, using the reagent itself as solvent [Zuhayra et al. (2008). Inorg. Chem. 47, 10177 – 10182]. On the basis of an X-ray analysis of the product, a molecular structure was proposed with two bridging carbonyls displaying very unusual geometrical features, not explained at the time. Subsequent chemical considerations, coupled with density functional theory (DFT) calculations, prompted us to revise the original ...
Source: Acta Crystallographica Section C - September 18, 2023 Category: Chemistry Authors: Zuhayra, M. L ü tzen, A. Ruiz, M.A. Tags: technetium crystal structure carbonyl pyridine methoxide research papers Source Type: research
A structural comparison of salt forms of dopamine with the structures of other phenylethylamines
The structures of four salt forms of dopamine are reported. These are dopamine [2-(3,4-dihydroxyphenyl)ethan-1-aminium] benzoate, C8H12NO2+ · C7H5O2 − , I, dopamine 4-nitrobenzoate, C8H12NO2+ · C7H4NO4 − , II, dopamine ethanedisulfonate, 2C8H12NO2+ · C2H4O6S22 − , III, and dopamine 4-hydroxybenzenesulfonate monohydrate, C8H12NO2+ · C6H5O4S − · H2O, IV. In all four structures, the dopamine cation adopts an extended conformation. Intermolecular interaction motifs that are common in the salt forms of tyramine can be found in related dopamine structures, but hydrogen bonding in the dopamine structures appear to be...
Source: Acta Crystallographica Section C - September 11, 2023 Category: Chemistry Authors: Kennedy, A.R. Cruickshank, L. Maher, P. McKinnon, Z. Tags: crystal structure active pharmaceutical ingredient API salt selection form selection dopamine phenylethylamine research papers Source Type: research
From liquid to crystal via mechanochemical grinding: unique host – guest (HOF) cocrystal
Mechanochemical synthesis via grinding of trimesic acid (TA, C9H6O6) and 4-chlorophenyl diphenyl phosphate (4CDP, C18H14ClO4P) (liquid at room temperature) in a 1:1 ratio resulted in the formation of an inclusion type of cocrystal. The crystallization of this phase via slow evaporation at low temperature (276 – 277 K) from methanol resulted in a rare `stairstep morphology' during the process of crystal growth. This morphology was not observed after crystallization of the compound from other solvents like toluene, dichloromethane, acetone, hexane and isooctane, and hence this was characteristically observed in methano...
Source: Acta Crystallographica Section C - September 4, 2023 Category: Chemistry Authors: Som, S. Hasija, A. Chopra, D. Tags: mechanochemical synthesis trimesic acid phosphate cocrystal crystal structure stairstep morphology crystalline sponge HOF research papers Source Type: research
2,2 ′ -Dithiobispyrazine: about the disulfide bond
X-ray diffraction studies reveal that pyrazine-2-thiol undergoes condensation to 2,2 ′ -dithiobispyrazine [systematic name: 2-(pyrazin-2-yldisulfanyl)pyrazine], C8H6N4S2 (I), under aerial conditions. In the molecule of I, the pyrazine rings are arranged in an almost perpendicular manner, with an absolute value of the C — S — S — C torsion angle of − 91.45 (6) ° . A search in the Cambridge Structural Database confirmed that such a conformation is typical for disulfide compounds. Three different rotamers of disulfide I were studied using quantum theoretical studies. The rotamer of lowest energy was observed in...
Source: Acta Crystallographica Section C - August 29, 2023 Category: Chemistry Authors: Wzgarda-Raj, K. Dominikowska, J. Husik, N. Rybarczyk-Pirek, A.J. Tags: 2,2 ′ -dithiobispyrazine crystal structure disulfide bond chalcogen bond quantum-chemical calculations SN2 mechanism research papers Source Type: research
Hemilability and structural considerations in complexes of platinum(II) comprising bis(diphenylphosphanyl)methane monoxide, monosulfide, and monoselenide
The structure of a platinum(II) complex containing (R)-(dimethylamino)ethylnapthyl and bis(diphenylphosphanyl)methane monosulfide ligands, namely, {(R)-1-[1-(dimethylamino)ethyl]napthyl- κ 2N,C2}[(diphenylphosphanylmethyl)diphenylphosphine sulfide- κ 2P,S]platinum(II) hexafluoridoantimonate dichloromethane monosolvate, [Pt(C14H16N)(C25H22P2S)][SbF6] · CH2Cl2, was determined. The structural features are compared with analogous platinum bis(diphenylphosphanyl)methane monoxide [dppm(O)] and bis(diphenylphosphanyl)methane monoselenide [dppm(Se)] complexes in relation to their potential hemilability and stereochemical nonrig...
Source: Acta Crystallographica Section C - August 26, 2023 Category: Chemistry Authors: Faller, J. Parr, J. Tags: hemilability platinum complex crystal structure phosphine sulfide oxide selenide research papers Source Type: research
Pathological crystal structures
Recent decades have seen enormous changes in the technology of crystal structure analysis, but the interpretation of these data still depends on human judgment, and errors are far from uncommon. Although analysing the crystallographic results with available software tools can catch many types of errors, others can be detected only by combining the knowledge of both crystallography and chemistry. We discuss several such examples from the published literature, and for each of them we identify what lessons they teach us. The examples are categorized by the type of error: correct crystallography but incorrect chemistry, wrong ...
Source: Acta Crystallographica Section C - August 23, 2023 Category: Chemistry Authors: Raymond, K.N. Girolami, G.S. Tags: crystallographic errors atom misassignments incorrect modeling disordered guest molecules incorrect space group incorrect cell size checkCIF topical reviews Source Type: research
