Synthesis and crystal structures of new chiral 3-amino-2H-azirines and the Pd complex of one of them
3-Amino-2H-azirines are potentially versatile building blocks in heterocyclic and peptide synthesis. Three new 3-amino-2H-azirines have been synthesized as racemates or mixtures of diastereoisomers in cases where another chiral residue is incorporated as the exocyclic amine. The crystal structures of two of them, an approximately 1:1 diastereoisomeric mixture of (2R)- and (2S)-2-ethyl-3-[(2S)-2-(1-methoxy-1,1-diphenylmethyl)pyrrolidin-1-yl]-2-methyl-2H-azirine, C23H28N2O, 11, and 2-benzyl-3-(N-methyl-N-phenylamino)-2-phenyl-2H-azirine, C22H20N2, 12, and the third as its diastereoisomeric trans-PdCl2 complex, trans-dichlori...
Source: Acta Crystallographica Section C - February 23, 2023 Category: Chemistry Authors: Linden, A. Bucher, C.B. Gubler, R. Villalgordo, J.M. Heimgartner, H. Tags: 3-amino-2H-azirines azirine rings crystal structure diastereoisomers Pd – azirine complex organic synthesis research papers Source Type: research
Conversion of 2-methyl-4-styrylquinolines into 2,4-distyrylquinolines: synthesis, and spectroscopic and structural characterization of five examples
Four new 2,4-distyrylquinolines and one 2-styryl-4-[2-(thiophen-2-yl)vinyl]quinoline have been synthesized using indium trichloride condensation reactions between aromatic aldehydes and the corresponding 2-methylquinolines, which were themselves prepared using Friedl ä nder annulation reactions between mono- or diketones and (2-aminophenyl)chalcones: the products have all been fully characterized by spectroscopic and crystallographic methods. 2,4-Bis[(E)-styryl]quinoline, C25H19N, (IIa), and its dichloro analogue, 2-[(E)-2,4-dichlorostyryl]-4-[(E)-styryl]quinoline, C25H17Cl2N, (IIb), exhibit different orientations of the ...
Source: Acta Crystallographica Section C - February 22, 2023 Category: Chemistry Authors: Vera, D.R. Ardila, D.M. Palma, A. Cobo, J. Glidewell, C. Tags: heterocyclic compounds synthesis quinolines styrylquinolines NMR spectroscopy crystal structure molecular conformation hydrogen bonding supramolecular assembly privilaged scaffold research papers Source Type: research
Optimizing disordered crystal structures
(Source: Acta Crystallographica Section C)
Source: Acta Crystallographica Section C - February 21, 2023 Category: Chemistry Authors: Linden, A. Tags: disorder disorder modelling whole molecule disorder commentary scientific commentaries Source Type: research
Dibromomethyl- and bromomethyl- or bromo-substituted benzenes and naphthalenes: C — Br...Br interactions
The structures of six benzene and three naphthalene derivatives involving bromo, bromomethyl and dibromomethyl substituents, namely, 1,3-dibromo-5-(dibromomethyl)benzene, C7H4Br4, 1,4-dibromo-2,5-bis(bromomethyl)benzene, C8H4Br6, 1,4-dibromo-2-(dibromomethyl)benzene, C7H4Br4, 1,2-bis(dibromomethyl)benzene, C8H6Br4, 1-(bromomethyl)-2-(dibromomethyl)benzene, C8H7Br3, 2-(bromomethyl)-3-(dibromomethyl)naphthalene, C12H9Br3, 2,3-bis(dibromomethyl)naphthalene, C12H8Br4, 1-(bromomethyl)-2-(dibromomethyl)naphthalene, C12H9Br3, and 1,3-bis(dibromomethyl)benzene, C8H6Br4, are presented. The packing patterns of these compounds are do...
Source: Acta Crystallographica Section C - February 15, 2023 Category: Chemistry Authors: Ku ś , P. Jones, P.G. Kusz, J. Ksi ą ż ek, M. Tags: crystal structure halogen bonds weak hydrogen bonds secondary interactions benzene naphthalene research papers Source Type: research
(E,E)-1,1 ′ -[1,2-Bis(4-chlorophenyl)ethane-1,2-diyl]bis(phenyldiazene) revisited: threefold configurational disorder of (S,S), (R,R) and (S,R) isomers, a detailed critique
Crystal structures described as concomitant triclinic (I) and monoclinic (II) polymorphs of meso-(E,E)-1,1 ′ -[1,2-bis(4-chlorophenyl)ethane-1,2-diyl]bis(phenyldiazene) [Mohamed et al. (2016). Acta Cryst. C72, 57 – 62] have been re-investigated. The published model for II was distorted due to forcing the symmetry of space group C2/c on an incomplete structure model. It is shown here to be a likely three-component superposition of S,S and R,R enantiomers with a lesser amount of the meso form. A detailed analysis of how the improbable distortion in the published model aroused suspicion and the subsequent construction of ...
Source: Acta Crystallographica Section C - February 15, 2023 Category: Chemistry Authors: Parkin, S. Glidewell, C. Horton, P.N. Tags: configurational disorder whole-molecule disorder correction polymorphism crystal structure research papers Source Type: research
Crystal structure and characterization of the sulfamethazine – piperidine salt
We report here the crystal structure and solid-state characterization of the 1:1 salt piperidinium sulfamethazinate (PPD+ · SUL − , C5H12N+ · C12H13N4O2S − ) (I). The salt was obtained by the solvent-assisted grinding method and was characterized by IR spectroscopy, powder X-ray diffraction, solid-state 13C NMR spectroscopy and thermal analysis [differential scanning calorimetry (DSC) and thermogravimetric analysis (TGA)]. Salt I crystallized in the monoclinic space group P21/n and showed a 1:1 stoichiometry revealing proton transfer from SUL to PPD to form salt I. The PPD+ and SUL − ions are connected by N — H+....
Source: Acta Crystallographica Section C - February 10, 2023 Category: Chemistry Authors: Gonz á lez-Gonz á lez, J.S. P é rez-Espinoza, S. Mart í nez-Mart í nez, F.J. Pineda-Contreras, A. Canseco-Mart í nez, M. Á . Flores-Alamo, M. Garc í a-Ortega, H. Tags: sulfamethazine piperidine IR spectroscopy crystal structure solid-state 13C NMR thermal analysis proton transfer solvent-assisted grinding research papers Source Type: research
Crystal structure of potassium chloride monohydrate: water intercalation into the B1 structure of KCl under high pressure. Corrigendum
In the paper by Yamashita et al. [Acta Cryst. (2022), C78, 749 – 754], an incorrect phrase is updated. (Source: Acta Crystallographica Section C)
Source: Acta Crystallographica Section C - January 30, 2023 Category: Chemistry Authors: Yamashita, K. Komatsu, K. Kagi, H. Tags: salt hydrate high pressure intercalation crystal structure potassium chloride addenda and errata Source Type: research
Supramolecular interactions in salts/cocrystals involving pyrimidine derivatives of sulfonate/carboxylic acid
The crystal structures of three compounds involving aminopyrimidine derivatives are reported, namely, 5-fluorocytosinium sulfanilate – 5-fluorocytosine – 4-azaniumylbenzene-1-sulfonate (1/1/1), C4H5FN3O+ · C6H6NO3S − · C4H4FN3O · C6H7NO3S, I, 5-fluorocytosine – indole-3-propionic acid (1/1), C4H4FN3O · C11H11NO2, II, and 2,4,6-triaminopyrimidinium 3-nitrobenzoate, C4H8N5+ · C7H4NO4 − , III, which have been synthesized and characterized by single-crystal X-ray diffraction. In I, there are two 5-fluorocytosine (5FC) molecules (5FC-A and 5FC-B) in the asymmetric unit, with one of the protons disordered between ...
Source: Acta Crystallographica Section C - January 23, 2023 Category: Chemistry Authors: Mohana, M. Thomas Muthiah, P.. McMillen, C.D. Butcher, R.J. Tags: hydrogen bonding zwitterion triple hydrogen bonds base pair homosynthon heterosynthon π – stacking crystal structure research papers Source Type: research
X-ray studies of three 3,6-bis(pyridin-2-yl)-1,2,4,5-tetrazine cocrystals: an unexpected molecular conformation stabilized by hydrogen bonds
The results of the X-ray structure analysis of three novel 3,6-bis(pyridin-2-yl)-1,2,4,5-tetrazine cocrystals are presented. These are 3,6-bis(pyridin-2-yl)-1,2,4,5-tetrazine – 2,4,6-tribromophenol (1/2), C12H8N6 · 2C6H3Br3O, 3,6-bis(pyridin-2-yl)-1,2,4,5-tetrazine – isonicotinic acid N-oxide (1/2), C12H8N6 · 2C6H5NO3, and 3,6-bis(pyridin-2-yl)-1,2,4,5-tetrazine – 4-nitrobenzenesulfonamide (1/1), C12H8N6 · C6H6N2O4S. Special attention is paid to a conformational analysis of the title tetrazine molecule in known crystal structures. Quantum chemistry methods are used to compare the energetic parameters of the invest...
Source: Acta Crystallographica Section C - January 18, 2023 Category: Chemistry Authors: Wzgarda-Raj, K. Dominikowska, J. Wojtulewski, S. Rybarczyk-Pirek, A.J. Tags: 3,6-bis(pyridin-2-yl)-1,2,4,5-tetrazine halogen bonding hydrogen bonding crystal structure quantum-chemical calculations research papers Source Type: research
High-resolution structural study on pyridin-3-yl ebselen and its N-methylated tosylate and iodide derivatives
The crystal structure of the pyridine-substituted benzisoselenazolinone 2-(pyridin-3-yl)-2,3-dihydro-1,2-benzoselenazol-3-one (C12H8N2OSe, 2), related to the antioxidant ebselen [systematic name: 2-phenyl-1,2-benzoselenazol-3(2H)-one, 1], is characterized by strong intermolecular N...Se( — N) chalcogen bonding, where the N...Se distance of 2.3831 (6) Å is well within the sum of the van der Waals radii for N and Se (3.34 Å ). This strong interaction results in significant lengthening of the internal N — Se distance, consistent with significant population of the Se — N σ * antibonding orbital. Much weake...
Source: Acta Crystallographica Section C - January 18, 2023 Category: Chemistry Authors: Xu, R. Fellowes, T. White, J.M. Tags: crystal structure chalcogen bonding hydrogen bonding multipole refinement electron density ebselen selenium research papers Source Type: research
Cocrystals assembled from iodoperfluorobenzene and flexible NTPO via halogen and π -hole bonds
Two binary cocrystals of 1,4-diiodotetrafluorobenzene (1,4-DITFB, C6F4I2) and 1,3,5-trifluoro-2,4,6-triiodobenzene (1,3,5-TITFB, C6F3I3) with the flexible 2-{[(naphthalen-2-yl)methyl]sulfanyl}pyridine 1-oxide (NTPO, C16H13NOS) molecule were successfully prepared and characterized by X-ray diffraction and quantum chemistry calculation methods. X-ray diffraction analysis reveals that the conformation of the flexible NTPO molecule has been changed significantly after introducing the 1,4-DITFB or 1,3,5-TITFB molecule into the NTPO lattice. Also the formation of the binary cocrystals is driven mainly by robust C — I... − O ...
Source: Acta Crystallographica Section C - January 13, 2023 Category: Chemistry Authors: Wang, H. Wu, W.X. Jin, W.J. Tags: crystal structure σ -hole bond π supramolecular chemistry AIM analysis cocrystal iodoperfluorobenzene NTPO research papers Source Type: research
Acta Crystallographica Section C: Chemistry Matters
(Source: Acta Crystallographica Section C)
Source: Acta Crystallographica Section C - January 12, 2023 Category: Chemistry Authors: Raithby, P.R. Tags: editorial crystallography chemistry Source Type: research
Chalcogen bonding in the solid-state structures of 1,3-bis(benzimidazoliumyl)benzene-based chalcogen-bonding donors
1,3-Bis(benzimidazoliumyl)benzene-based chalcogen-bonding catalysts were previously successfully applied in different benchmark reactions. In one of those examples, i.e. the activation of quinolines, sulfur- and selenium-based chalcogen-bonding catalysts showed comparable properties, which is unexpected, as the selenium-containing catalysts should show superior catalytic properties due to the increased polarizability of selenium compared to sulfur. Herein, we present four crystal structures of the respective 1,3-bis(benzimidazoliumyl)benzene-based chalcogen-bonding catalyst containing sulfur (3S) and selenium (3Se, three f...
Source: Acta Crystallographica Section C - January 11, 2023 Category: Chemistry Authors: Steinke, T. Engelage, E. Huber, S.M. Tags: chalcogen bonding Lewis acid crystal structure sigma hole intermolecular interactions benzimidazolium research papers Source Type: research
Structure and charge analysis of a cyclic aluminium hydride: cyclo-1,5-bis- μ -dimethylamino-3,7-di- μ -hydrido-2,4,6,8-tetrakis(dimethylaluminium)
The title compound, [Al4(CH3)8(C2H7N)2H2], crystallizes as eight-membered rings with – (CH3)2Al – (CH3)2N – (CH3)2Al – moieties connected by single hydride bridges. In the X-ray structure, the ring has a chair conformation, with the hydride H atoms being close to the plane through the four Al atoms. An optimized structure was also calculated by all-electron density functional theory (DFT) methods, which agrees with the X-ray structure but gives a somewhat different geometry for the hydride bridge. Charges on the individual atoms were determined by valence shell occupancy refinements using MoPro and also by DFT calc...
Source: Acta Crystallographica Section C - December 14, 2022 Category: Chemistry Authors: Corfield, P.W.R. Schrier, J. Tags: crystal structure hydride bridge organoaluminium DFT charge determination research papers Source Type: research
A three-step pathway from (2-aminophenyl)chalcones to novel styrylquinoline – chalcone hybrids: synthesis and spectroscopic and structural characterization of three examples
Three new styrylquinoline – chalcone hybrids have been synthesized using a three-step pathway starting with Friedl ä nder cyclocondensation between (2-aminophenyl)chalcones and acetone to give 2-methyl-4-styrylquinolines, followed by selective oxidation to the 2-formyl analogues, and finally Claisen – Schmidt condensation between the formyl intermediates and 1-acetylnaphthalene. All intermediates and the final products have been fully characterized by IR and 1H/13C NMR spectroscopy, and by high-resolution mass spectrometry, and the three products have been characterized by single-crystal X-ray diffraction. The molecul...
Source: Acta Crystallographica Section C - December 8, 2022 Category: Chemistry Authors: Vera, D.R. Mantilla, J.P. Palma, A. D í az Costa, I. Cobo, J. Glidewell, C. Tags: synthesis quinoline styrylquinoline chalcone NMR spectroscopy crystal structure molecular structure molecular conformation hydrogen bonding π – stacking interactions supramolecular assembly research papers Source Type: research
