Crystal and mesophase structure of a bicyclohexyl cyano mesogen
The phase behaviour of 4-[trans-4-(trans-4-propylcyclohexyl)cyclohexyl]benzonitrile, C22H31N, 1, has been examined. This compound has two different solid phases, denoted I and II, and exhibits thermotropic liquid-crystalline behaviour, with a remarkable interval of stability of the mesophase between the lower melting solid phase (75 ° C) and the isotropization temperature (247 ° C). The crystal and molecular structures of solid phase I have been determined at 173 K. The cyclohexyl rings both adopt the chair conformation and are equatorially substituted. The packing of 1 in the crystalline state is driven by t...
Source: Acta Crystallographica Section C - October 24, 2022 Category: Chemistry Authors: Gupta, S. Das, P.P. Crispini, A. Scarpelli, F. Borbone, F. Centore, R. Tags: mesogen texture crystal packing ordered smectics crystal structure benzonitrile research papers Source Type: research
Carbon-atom hybridization tunes the halogen-bond strength in the series of DABCO · C2H2nI2 (n = 0 – 2) cocrystals
Two new cocrystals of 1,4-diazabicyclo[2.2.2]octane (DABCO, C6H12N2) with 1,2-diiodoethene (1,2-C2H2I2) and 1,2-diiodoethane (1,2-C2H4I2) complete a series of halogen-bond-assisted cocrystals which started with DABCO · C2I2 [Perkins et al. (2012). CrystEngComm, 14, 3033 – 3038]. The structural and computational analysis of this series illustrate the correlation between the polarization of the I atom and the hybridization of the C atom bound to it. The formation of a rather stable halogen bond by the alkylic iodide of saturated 1,2-C2H4I2 was unusual and respective cocrystals are formed only in nonpolar solvents, while, ...
Source: Acta Crystallographica Section C - October 19, 2022 Category: Chemistry Authors: Torubaev, Y. Skabitskiy, I. Tags: halogen bonding cocrystal noncovalent interaction MEP molecular electrostatic potential crystal structure DABCO diiodoethane diiodoethene research papers Source Type: research
Isolation and crystal and molecular structures of [(C5H2Br3)2Fe], [(C5HBr4)2Fe] and [(C5Br5)(C5Br4HgBr)Fe]
The reaction of [(C5H3Br2)2Fe] with lithium tetramethylpiperidinide (LiTMP) in a 1:10 molar ratio in tetrahydrofuran yields, after quenching with C2H2Br4, a mixture of the polybromoferrocenes [C10H10 – nBrnFe] with n = 4 – 9, from which single crystals of bis(1,2,3-tribromocyclopentadienyl)iron(II), [Fe(C5H2Br3)2], and bis(1,2,3,4-tetrabromocyclopentadienyl)iron(II), [Fe(C5HBr4)2Fe], were obtained by a combination of chromatography and fractional crystallization. Treatment of `[C10(HgOAc)10Fe]' with KBr3 yields a mixture of polybromoferrocenes [C10H10 – nBrnFe] with n = 8 – 10 and bromomercurioferrocenes [C10...
Source: Acta Crystallographica Section C - October 13, 2022 Category: Chemistry Authors: Blockhaus, T. S ü nkel, K. Tags: noncovalent interactions halogen bonding Hirshfeld analysis crystal structure bromoferrocene research papers Source Type: research
3,4-Bis-O-propargyl-1,2:5,6-di-O-isopropylidene-d-mannitol: a study of multiple weak hydrogen bonds in the solid state
The title homochiral compound, C18H26O6, 1, was examined by single-crystal X-ray crystallography in order to understand its potential as a synthetic building block, particularly in inter- and intramolecular cyclocondensation reactions. It has also proven to be an excellent model for understanding multiple weak donor – acceptor D — H...A interactions involving terminal acetylenes as donors and as acceptors. The asymmetric unit of 1 comprises three almost identical independent molecules, each with the mannitol 2R,3R,4R,5R configuration and different conformations. Like independent molecules align in strands through acety...
Source: Acta Crystallographica Section C - October 11, 2022 Category: Chemistry Authors: Mohammed, A.I. Bhadbhade, M.M. Read, R.W. Tags: chemical crystallography weak hydrogen bonds noncovalent interactions crystal structure crystal engineering supramolecular chemistry CSD research papers Source Type: research
On the use of Hirshfeld surfaces for estimating atomic charges in ionic species: crystal structure of the natural ilmenite (Mg0.4168Fe0.5832)TiO3
We performed an analysis by single-crystal X-ray diffraction and scanning electron microscopy (SEM), aiming to solve and refine the structure of an ilmenite single crystal [(Fe0.5832Mg04168)TiO3] from the city of Ouvidor (Goi á s, Brazil). Hirshfeld partition was used to explore the values of w(r), dnorm and curvedness that achieve complementary surfaces for neighbouring atoms in this ionic system, and the subsequent impact on the charge distribution, allowing the ionic radius and the charges of the ilmenite sample to be modelled. (Source: Acta Crystallographica Section C)
Source: Acta Crystallographica Section C - October 7, 2022 Category: Chemistry Authors: Almeida, L.F. de Rodrigues, B.L. Tags: ilmenite geikielite Hirshfeld surface crystal structure ionic charge structure refinement research papers Source Type: research
CdII-based compound as a multi-responsive fluorescent probe for sensing FeIII cations and CrVI oxyanions
A new luminescent CdII compound, poly[[ μ 2-1,4-bis(1H-imidazol-1-yl)benzene]{ μ 2-5-[(3-carboxylphenoxy)methyl]isophthalato}cadmium(II)], [Cd(C16H10O7)(C12H10N4)]n or [Cd(HL)(1,4-bib)]n {H3L is 5-[(3-carboxyphenoxy)methyl]isophthalic acid and 1,4-bib is 1,4-bis(1H-imidazol-1-yl)benzene}, I, has been synthesized successfully from CdII and a semirigid tricarboxylic ligand under hydrothermal conditions. Structure analysis shows that I is a two-dimensional structure with the point symbol {44.62}. The three-dimensional framework is constructed by O — H...O hydrogen bonds and π – π stacking interactions. Furthermore, th...
Source: Acta Crystallographica Section C - October 7, 2022 Category: Chemistry Authors: An, Y.-Y. Su, L.-J. Zhao, X. Yan, J.-Z. Tags: isophthalic acid cadmium hydrothermal synthesis selective luminescence quenching crystal structure research papers Source Type: research
Single-crystal structure refinements and Debye temperatures of Ir2S3 kashinite and Rh2S3 bowieite
Single crystals of Ir2S3 (diiridium trisulfide) and Rh2S3 (dirhodium trisulfide) were grown in evacuated silica-glass tubes using a chemical transport method and their crystal structures were determined by single-crystal X-ray diffraction analysis. These compounds have a unique sesquisulfide structure in which pairs of face-sharing octahedra are linked into a three-dimensional structure by further edge- and vertex-sharing. Ir2S3 and Rh2S3 had similar unit-cell parameters and bond distances. The atomic displacement parameter (MSD: mean-square displacement) of each atom in Ir2S3 was considerably smaller than that in Rh2S3. T...
Source: Acta Crystallographica Section C - October 6, 2022 Category: Chemistry Authors: Yoshiasa, A. Kitahara, G. Tokuda, M. Ishimaru, S. Ono, S. Terai, K. Nakatsuka, A. Sugiyama, K. Tags: iridium rhodium sulfide kashinite bowieite crystal structure Debye temperature research papers Source Type: research
Ab initio calculation of mechanical, electronic and optical characteristics of chalcogenide perovskite BaZrS3 at high pressures
A theoretical examination of the structural, elastic, electronic and optical properties of the chalcogenide perovskite BaZrS3 under pressures of 0 and 20 GPa was performed using density functional theory ab initio calculations. The lattice constants of the BaZrS3 structure are well reproduced from our first-principles calculations and are in excellent agreement with experimental measurements. Moreover, the values of mechanical parameters, such as the elastic constant, increased under applied pressure. The electronic parameters indicate that the chalcogenide perovskite BaZrS3 has a direct band gap of 1.75 eV. To und...
Source: Acta Crystallographica Section C - September 27, 2022 Category: Chemistry Authors: Rong, Z. Zhi, C. Jun, C. Tags: chalcogenide perovskite electronic properties density functional theory high pressure optical properties semiconductor research papers Source Type: research
Structure and cytotoxic properties of 1-hydroxy-5-methyl-7-phenylpyrido[3,4-d]pyridazin-4(3H)-one and its mono- and disubstituted ethyl acetates
Derivatives of pyrido[3,4-d]pyridazine, namely, 1-hydroxy-5-methyl-7-phenylpyrido[3,4-d]pyridazin-4(3H)-one dimethylformamide monosolvate, C14H11N3O2 · C3H7NO (2), ethyl [1-(2-ethoxy-2-oxoethoxy)-5-methyl-4-oxo-7-phenyl-3,4-dihydropyrido[3,4-d]pyridazin-3-yl]acetate, C18H17N3O4 (3), and ethyl [(5-methyl-4-oxo-7-phenyl-3,4-dihydropyrido[3,4-d]pyridazin-1-yl)oxy]acetate, C22H23N3O6 (4), were synthesized with the aim of discovering new potential biologically active agents. The properties of all three derivatives were characterized by 1H NMR, 13C NMR and FT – IR spectroscopic analysis. All the crystals were obtained by a so...
Source: Acta Crystallographica Section C - September 23, 2022 Category: Chemistry Authors: W ó jcicka, A. Becan, L. Rembia ł kowska, N. Pyra, A. Bryndal, I. Tags: pyrido[3,4-d]pyridazine derivatives synthesis N-alkylation O-alkylation crystal structure cytotoxic activity research papers Source Type: research
A structural and computational comparison of close contacts and related intermolecular energies of interaction in the structures of 1,3-diiodo-5-nitrobenzene, 1,3-dibromo-5-nitrobenzene, and 1,3-dichloro-5-nitrobenzene
1,3-Diiodo-5-nitrobenzene, C6H3I2NO2, and 1,3-dibromo-5-nitrobenzene, C6H3Br2NO2, crystallize in the centrosymmetric space group P21/m, and are isostructural with 1,3-dichloro-5-nitrobenzene, C6H3Cl2NO2, that has been redetermined at 100 K for consistency. While the three-dimensional packing in all three structures is similar, the size of the halogen atom affects the nonbonded close contacts observed between molecules. Thus, the structure of 1,3-diiodo-5-nitrobenzene features a close Type 1 I...I contact, the structure of 1,3-dibromo-5-nitrobenzene features a self-complementary nitro-O...Br close contact, while the str...
Source: Acta Crystallographica Section C - September 23, 2022 Category: Chemistry Authors: Bosch, E. Bowling, N.P. Speetzen, E.D. Tags: crystal structure — H hydrogen bonding halogen bond – halogen interaction self-complementary halogen bond bifurcated C H...nitro hydrogen bond Hirshfeld surface intermolecular energy energy frameworks research papers Source Type: research
The centre cannot hold
(Source: Acta Crystallographica Section C)
Source: Acta Crystallographica Section C - September 13, 2022 Category: Chemistry Authors: Mar, A. Tags: noncentrosymmetric diamond-like semiconductors nonlinear optical materials scientific commentaries Source Type: research
Crystal structure and antidiabetic activity of 2-aminospiropyrazolinium tosylates and the product of O-tosylation of β -(benzimidazol-1-yl)propioamidoxime
2-Amino-1,5-diazaspiro[4.5]dec-1-en-5-ium salts possess bioactivity tuned by the nature of the heteroatoms in the six-membered ring and the counter-ion. The molecular environment of these cations in solids provides an opportunity to establish the conformations and hydrogen-bonding patterns typical for this family. β -Aminopropioamidoxime tosylation products [2-amino-1,5-diazaspiro[4.5]dec-1-en-5-ium tosylates and the product of the O-tosylation of β -(benzimidazol-1-yl)propioamidoxime, namely, 2-amino-1,5-diazaspiro[4.5]dec-1-en-5-ium tosylate, C8H16N3+ · C7H7O3S − (6), 2-amino-8-oxa-1,5-diazaspiro[4.5]dec-1-en-5-ium ...
Source: Acta Crystallographica Section C - September 11, 2022 Category: Chemistry Authors: Kayukova, L.A. Vologzhanina, A.V. Yergaliyeva, E.M. Baitursynova, G.P. Shulgau, Z.T. Sergazy, S. Tags: antidiabetic activity 2-aminospiropyrazolinium salts crystal structure hydrogen bonding hydrogen-bond formation tosylate research papers Source Type: research
Chemical characterization, absolute configuration and optical purity of (1S)-(+)- and (1R)-( – )-10-camphorsulfonic acid
Comprehensive chemical characterization for two isomers of camphorsulfonic acid (CSA), occasionally used in the manufacture of active pharmaceutical ingredients (APIs), was performed by nuclear magnetic resonance (NMR) spectroscopy, high-resolution mass spectroscopy in negative electrospray ionization mode and gas chromatography/mass spectrometry (GC/MS) in electron ionization mode. Electronic circular dichroism (ECD) spectra together with quantum chemical calculations using time-dependent density functional theory (TD-DFT) were used to assign the stereochemistry for CSA for the first time and these assignments were then c...
Source: Acta Crystallographica Section C - September 11, 2022 Category: Chemistry Authors: Cheng, H. Yan, D. Wu, L. Liang, P. Cai, Y. Li, L. Tags: camphorsulfonic acid NMR MS electronic circular dichroism DFT crystal structure characterization optical purity research papers Source Type: research
77Se and 125Te solid-state NMR and X-ray diffraction structural study of chalcogen-bonded 3,4-dicyano-1,2,5-chalcogenodiazole cocrystals
Three novel chalcogen-bonded cocrystals featuring 3,4-dicyano-1,2,5-selenodiazole (C4N4Se) or 3,4-dicyano-1,2,5-tellurodiazole (C4N4Te) as chalcogen-bond donors and hydroquinone (C6H6O2), tetraphenylphosphonium chloride (C24H20P+ · Cl − ) or tetraethylphosphonium chloride (C8H20P+ · Cl − ) as chalcogen-bond acceptors have been prepared and characterized by single-crystal X-ray diffraction (XRD), powder X-ray diffraction and 77Se/125Te magic-angle spinning solid-state NMR spectroscopy. The single-crystal XRD results show that the chalcogenodiazole molecules interact with the electron donors through two σ -holes on ea...
Source: Acta Crystallographica Section C - September 10, 2022 Category: Chemistry Authors: Nag, T. Ovens, J.S. Bryce, D.L. Tags: chalcogen bond noncovalent interaction selenium tellurium crystal structure research papers Source Type: research
Synthesis and spectroscopic and structural characterization of three new 2-methyl-4-styrylquinolines formed using Friedl ä nder reactions between (2-aminophenyl)chalcones and acetone
Three new 2-methyl-4-styrylquinoline derivatives have been synthesized in high yields using Friedl ä nder reactions between chalcones [1-(2-aminophenyl)-3-arylprop-2-en-1-ones] and acetone, and characterized using IR, 1H and 13C NMR spectroscopy, and mass spectrometry, and by crystal structure analysis. In (E)-4-(4-fluorostyryl)-2-methylquinoline, C18H14FN, (I), the molecules are joined into cyclic centrosymmetric dimers by C — H...N hydrogen bonds and these dimers are linked into sheets by π – π stacking interactions. The molecules of (E)-2-methyl-4-[4-(trifluoromethyl)styryl]quinoline, C19H14F3N, (II), are linked ...
Source: Acta Crystallographica Section C - September 5, 2022 Category: Chemistry Authors: Vera, D.R. Mantilla, J.P. Palma, A. Cobo, J. Glidewell, C. Tags: synthesis quinoline Friedlander reaction NMR spectroscopy crystal structure molecular conformation hydrogen bonding supramolecular assembly research papers Source Type: research
