Concomitant polymorphs of 2-imino-2H-chromene-3-carboxylic acid amide: experimental and quantum chemical study
2-Iminocoumarin-3-carboxamide (2-imino-2 H-chromene-3-carboxylic acid) is a perspective compound for use in the pharmaceutical industry. This compound crystallized from several solvents as two concomitant polymorphic forms. The monoclinic polymorph, crystallized initially, is formed due to strong N — H...O hydrogen bonds, weak C — H...O and C — H...N( π ) hydrogen bonds, and stacking interactions of `head-to-head' type. The triclinic polymorphic form obtained due to slow evaporation of the same solution is formed due to only strong intermolecular interactions, N — H...O hydrogen bonds of two types, and stackin...
Source: Acta Crystallographica Section B - January 9, 2024 Category: Chemistry Authors: Shishkina, S.V. Shaposhnyk, A.M. Konovalova, I.S. Dyakonenko, V.V. Vaksler, Y.O. Tags: 2-iminocoumarin-3-carboxamide concomitant polymorphism pairwise interaction energies DFT calculations modeling of structure deformation research papers Source Type: research
Tailoring the dimensionality of metal complexes via ligand modifications
A series of CuII complexes obtained under the same reaction conditions has been analyzed to gain insight into the effect of the ligand composition on the final reaction product. Dipodal ligands containing N-donor imidazole rings and a benzene ring as a spacer with different numbers of methyl substituents on the aromatic rings were selected for the study such as 1,3-bis(imidazol-1-ylmethyl)benzene (L1), 1,3-bis(imidazol-1-ylmethyl)-5-methylbenzene (L2), 1,3-bis(imidazol-1-ylmethyl)-2,4,6-trimethylbenzene (L3), 1,3-bis(2-methylimidazol-1-ylmethyl)-2,4,6-trimethylbenzene (L4). L4 has not been reported previously and was synth...
Source: Acta Crystallographica Section B - January 5, 2024 Category: Chemistry Authors: Le Garff, P. Maria Losus, R. Chaudhary, S. Dobrza ń ska, L. Tags: dipodal ligands coordination polymers crystal engineering discrete metal complexes research papers Source Type: research
Lattice response to the radiation damage of molecular crystals: radiation-induced versus thermal expansivity
The interaction of intense synchrotron radiation with molecular crystals frequently modifies the crystal structure by breaking bonds, producing fragments and, hence, inducing disorder. Here, a second-rank tensor of radiation-induced lattice strain is proposed to characterize the structural susceptibility to radiation. Quantitative estimates are derived using a linear response approximation from experimental data collected on three materials Hg(NO3)2(PPh3)2, Hg(CN)2(PPh3)2 and BiPh3 [PPh3 = triphenylphosphine, P(C6H5)3; Ph = phenyl, C6H5], and are compared with the corresponding thermal expansivities. The associated eigenva...
Source: Acta Crystallographica Section B - January 4, 2024 Category: Chemistry Authors: McMonagle, C.J. Fuller, C.A. Hupf, E. Malaspina, L.A. Grabowsky, S. Chernyshov, D. Tags: radiation damage thermal expansion molecular crystals disorder research papers Source Type: research
High-throughput nanoscale crystallization of dihydropyridine active pharmaceutical ingredients
Single-crystal X-ray diffraction analysis of small molecule active pharmaceutical ingredients is a key technique in the confirmation of molecular connectivity, including absolute stereochemistry, as well as the solid-state form. However, accessing single crystals suitable for X-ray diffraction analysis of an active pharmaceutical ingredient can be experimentally laborious, especially considering the potential for multiple solid-state forms (solvates, hydrates and polymorphs). In recent years, methods for the exploration of experimental crystallization space of small molecules have undergone a `step-change', resulting in ne...
Source: Acta Crystallographica Section B - December 21, 2023 Category: Chemistry Authors: Metherall, J.P. Corner, P.A. McCabe, J.F. Hall, M.J. Probert, M.R. Tags: dihydropyridines high-throughput crystallization single-crystal X-ray diffraction small molecule encapsulated nanodroplet crystallization research papers Source Type: research
Non-crystallographic helices in polymers and close-packed metallic crystals determined by the four-dimensional counterpart of the icosahedron
Non-crystallographic fractional screw axes are inherent to the constructions of n-dimensional crystallography, where 3 (Source: Acta Crystallographica Section B)
Source: Acta Crystallographica Section B - November 28, 2023 Category: Chemistry Authors: Talis, A. Kucherinenko, Y. Tags: helices with fractional axes α -Mn and β -Mn crystals 4D {3, 5} polytope approximants of the polytope axes class of the fractional axes research papers Source Type: research
Electron traps and energy storage: modeling a bright path to the future
(Source: Acta Crystallographica Section B)
Source: Acta Crystallographica Section B - November 22, 2023 Category: Chemistry Authors: Moura Jr, R.T. Tags: luminescence electron trap doped materials TDDFT solid state lutetium oxide scientific commentaries Source Type: research
Design and synthesis of diverse Cd2+/Zn2+/Cu2+ coordination polymers tuned by dicarboxylate and auxiliary 1,4-bis(pyridin-4-ylmethyl)piperazine ligands with luminescence and Hirshfeld surface analyses
Four new coordination polymers, including 1D, 2D and 3D structures, were synthesized via a hydrothermal method using Cd2+/Zn2+/Cu2+ metal salts as nodes. These polymers were formed through self-assembly of four different dicarboxylic acid ligands, namely adamantane-1,3-dicarboxylic acid (H2adc), glutaric acid (H2glu), 5-hydroxyisophthalic acid (H2hip) and fumaric acid (H2fum), in conjunction with the auxiliary ligand [1,4-bis(pyridin-4-ylmethyl)piperazine (bpmp). The corresponding formulae are [Cd3(adc)2(bpmp)Cl2(H2O)2]n (1), {[Cd2(glu)2(bpmp)2(H2O)2] · 8H2O · 2CH3OH}n (2), [Zn(hip)(bpmp)(H2O)]n (3) and [Cu(fum)(bpmp)(H2...
Source: Acta Crystallographica Section B - November 15, 2023 Category: Chemistry Authors: Jin, N. Liu, Y. Dai, S. Li, Y. Wang, X. Zhao, Y. Liu, X. Chen, H. Luo, H. Li, W. Tags: dicarboxylate ligands N-containing ligands fluorescence Hirshfeld surface research papers Source Type: research
A drug – drug cocrystal and a co-amorphous form, prepared from honokiol and ligustrazine, inspired by Chinese patent medicine
A drug – drug cocrystal created with two antithrombotic-active ingredients from herbs, honokiol (HON) and ligustrazine (TMP, 1:1), was synthesized and characterized. The structure of HON – TMP (1:1) was determined by single-crystal X-ray diffraction. Then co-amorphous HON – TMP was prepared by honey-assisted grinding, which was inspired by a grinding process for a Chinese patent medicine-Shijunzi honey pill. This co-amorphous drug – drug cocrystal (20% honey) exhibits improved solubility over HON and a significantly reduced sublimation tendency than TMP. (Source: Acta Crystallographica Section B)
Source: Acta Crystallographica Section B - November 15, 2023 Category: Chemistry Authors: Zhang, Y. Liu, H. Chen, Z. Meng, J. Li, Y. Qi, L. Zhang, S. Chen, X. Lei, M. Tags: crystal engineering pharmaceutical cocrystal co-amorphous drug – drug interaction stability dissolution research papers Source Type: research
Order – disorder (OD) polytypism of K3FeTe2O8(OH)2(H2O)1+x
K3FeTe2O8(OH)2(H2O)2 was synthesized under hydrothermal conditions from Te(OH)6, FeSO4 · 7H2O and 85 wt% KOH in a 1:2:6 molar ratio. The crystal structure is built of a triperiodic network. One disordered water molecule per formula unit is located in a channel and can be partially removed by heating. Systematic one-dimensional diffuse scattering indicates a polytypic character, which is best described by application of the order – disorder theory. The major polytype is monoclinic with pseudo-orthorhombic metrics. It is interrupted by fragments of an orthorhombic polytype. The diffraction intensities are analyzed usi...
Source: Acta Crystallographica Section B - November 7, 2023 Category: Chemistry Authors: Wolflehner, T. St ö ger, B. Tags: polytypism OD theory X-ray diffraction tellurate research papers Source Type: research
A high-pressure single-crystal X-ray diffraction study of potassium guaninate hydrate, K+ · C5H4N5O − · H2O
The crystal structure of potassium guaninate hydrate, K+ · C5H4N5O − · H2O, was studied in the pressure range of 1 atm to 7.3 GPa by single-crystal diffraction using synchrotron radiation and a laboratory X-ray diffraction source. Structural strain was compared to that of the same salt hydrate on cooling, and in 2Na+ · C5H3N5O2 − · 7H2O under hydrostatic compression and on cooling. A polymorphic transition into a new, incommensurately modulated, phase was observed at ∼ 4 – 5 GPa. The transition was reversible with a hysteresis: the satellite reflections disappeared on decompression to ∼ 1.4 GP...
Source: Acta Crystallographica Section B - November 2, 2023 Category: Chemistry Authors: Gaydamaka, A.A. Rashchenko, S.V. Semerikova, A.I. Smirnova, E.S. Ivanova, A.G. Arkhipov, S.G. Zakharov, B.A. Bogdanov, N.E. Boldyreva, E.V. Tags: guanine high pressure XRD strain anisotropy nucleobase intermolecular interactions incommensurate modulation research papers Source Type: research
Ab initio crystal structures and relative phase stabilities for the aleksite series, PbnBi4Te4Sn+2
Density functional theory methods are applied to crystal structures and stabilities of phases from the aleksite homologous series, PbnBi4Te4Sn+2 (n = homologue number). The seven phases investigated correspond to n = 0 (tetradymite), 2 (aleksite-21R and -42R), 4 (saddlebackite-9H and -18H), 6 (unnamed Pb6Bi4Te4S8), 8 (unnamed Pb8Bi4Te4S10), 10 (hitachiite) and 12 (unnamed Pb12Bi4Te4S14). These seven phases correspond to nine single- or double-module structures, each comprising an odd number of atom layers, 5, 7, (5.9), 9, (7.11), 11, 13, 15 and 17, expressed by the formula: S(MpXp+1) · L(Mp+1Xp+2), where M = Pb, Bi an...
Source: Acta Crystallographica Section B - November 1, 2023 Category: Chemistry Authors: Yao, J. Ciobanu, C.L. Cook, N.J. Ehrig, K. Tags: aleksite series mixed layer compounds crystal structure density functional theory electron diffraction research papers Source Type: research
Incommensurate magnetic structure of CrAs at low temperatures and high pressures
The magnetic structure of chromium arsenide CrAs is studied with neutron powder diffraction at ambient pressure in the temperature range 1.5 – 300 K as well as with neutron single-crystal diffraction at 2 K and 0.12 GPa. The material undergoes an anti-isostructural phase transition at TN = 267 K and atmospheric conditions, in which both orthorhombic phases have the same space-group symmetry (Pnma, Z = 4) but different distortions of the parent hexagonal structure of the NiAs type (P63/mmc, Z = 2). The magnetic structure below TN is incommensurate with the propagation vector k = (0, 0, kc). At ambient pres...
Source: Acta Crystallographica Section B - October 11, 2023 Category: Chemistry Authors: Eich, A. Grzechnik, A. Su, Y. Ouladdiaf, B. Sheptyakov, D. Wolf, T. Petricek, V. Shahed, H. Friese, K. Tags: incommensurate magnetic structure neutron diffraction extreme conditions high pressure research papers Source Type: research
Hydrogen bonding patterns and C — H... π interactions in the structure of the antiparkinsonian drug (R)-rasagiline mesylate determined using laboratory and synchrotron X-ray powder diffraction data
The structure of (R)-rasagiline mesylate [(R)-RasH+ · Mes − ], an active pharmaceutical ingredient used to treat Parkinson's disease, is presented. The structure was determined from laboratory and synchrotron powder diffraction data, refined using the Rietveld method, and validated and optimized using dispersion-corrected DFT calculations. The unit-cell parameters obtained in both experiments are in good agreement and the refinement with both datasets converged to good agreement factors. The final parameters obtained from laboratory data were a = 5.4905 (8), b = 6.536 (2), c = 38.953 (3) Å , V = 1398.0 ...
Source: Acta Crystallographica Section B - October 11, 2023 Category: Chemistry Authors: Dugarte-Dugarte, A.J. Toro, R.A. van de Streek, J. Henao, J.A. Fitch, A.N. Dejoie, C. Delgado, J.M. D í az de Delgado, G. Tags: crystal structure rasagiline mesylate structure determination synchrotron radiation DFT-D calculations Hirshfeld surface analysis Parkinson's disease research papers Source Type: research
3D electron diffraction analysis of a novel, mechanochemically synthesized supramolecular organic framework based on tetrakis-4-(4-pyridyl)phenylmethane
This article describes a novel expanded form of a TPPM-based SOF that has been mechanochemically synthesized and whose crystal structure has been determined by 3D electron diffraction analysis using a novel electron diffractometer. (Source: Acta Crystallographica Section B)
Source: Acta Crystallographica Section B - October 11, 2023 Category: Chemistry Authors: Marchetti, D. Pedrini, A. Massera, C. Faye Diouf, M.D. Jandl, C. Steinfeld, G. Gemmi, M. Tags: 3D electron diffraction electron diffractometer mechanochemistry supramolecular organic frameworks research papers Source Type: research
Quantifying weak interactions in ferroelectric and paraelectric phases of phenazine and chloroanilic acid co-crystal using experimental and theoretical electron densities
The co-crystal of phenazine and chloroanilic acid is known to display paraelectric properties at room temperature. It shows a paraelectric to ferroelectric phase transition at 253 K and has an incommensurately modulated ferroelectric phase below 137 K. High-resolution synchrotron X-ray data were collected at 160 K to model the experimental electron-density distributions, and derived topological properties from the electron density were used to quantify the weak interactions responsible for the origin of the ferroelectric phase. The structure and non-covalent interactions are analysed using Hirshfeld surfaces an...
Source: Acta Crystallographica Section B - October 7, 2023 Category: Chemistry Authors: Anil Kumar, G.N. Hathwar, V.R. Tags: electron density co-crystals ferroelectric properties paraelectric properties hydrogen bonds research papers Source Type: research
