ChemInform Abstract: PENTACOORDINATED MOLECULES. 30. CRYSTAL AND MOLECULAR STRUCTURES OF SYMMETRICAL DIOXADIAZASPIROPHOSPHORANES CONTAINING PHOSPHORUS-HYDROGEN BONDS

1979 ◽  
Vol 10 (8) ◽  
Author(s):  
P. F. MEUNIER ◽  
R. O. DAY ◽  
J. R. DEVILLERS ◽  
R. R. HOLMES
Keyword(s):  
Hydrogen Bonds ◽  
Molecular Structures ◽  
Crystal And Molecular Structures

scholarly journals Crystal structures of the 1:1 salts of 2-amino-4-nitrobenzoate with each of (2-hydroxyethyl)dimethylazanium, tert-butyl(2-hydroxyethyl)azanium and 1,3-dihydroxy-2-(hydroxymethyl)propan-2-aminium

2018 ◽  
Vol 74 (12) ◽  
pp. 1735-1740 ◽  
Author(s):  
James L. Wardell ◽  
Edward R. T. Tiekink
Keyword(s):  
Hydrogen Bonds ◽  
Three Dimensional ◽  
Molecular Structures ◽  
Double Layers ◽  
Crystal And Molecular Structures ◽  
Ammonium N ◽  
Molecular Salts ◽  
Benzene Rings ◽  
The Common ◽  
Supramolecular Aggregation

The crystal and molecular structures of the title molecular salts, C4H12NO+·C7H5N2O4 −, (I), C6H16NO+·C7H5N2O4 −, (II), and C4H12NO3 +·C7H5N2O4 −, (III), are described. The common feature of these salts is the presence of the 2-amino-4-nitrobenzoate anion, which exhibit non-chemically significant variations in the conformational relationships between the carboxylate and nitro groups, and between these and the benzene rings they are connected to. The number of ammonium-N—H H atoms in the cations increases from one to three in (I) to (III), respectively, and this variation significantly influences the supramolecular aggregation patterns in the respective crystals. Thus, a linear supramolecular chain along [100] sustained by charge-assisted tertiary-ammonium-N—H...O(carboxylate), hydroxy-O—H...O(carboxylate) and amino-N—H...O(carboxylate) hydrogen-bonds is apparent in the crystal of (I). Chains are connected into a three-dimensional architecture by methyl-C—H...O(hydroxy) and π–π interactions, the latter between benzene rings [inter-centroid separation = 3.5796 (10) Å]. In the crystal of (II), a supramolecular tube propagating along [901] arises as a result of charge-assisted secondary-ammonium-N—H...O(carboxylate) and hydroxy-O—H...O(carboxylate) hydrogen-bonding. These are connected by methylene- and methyl-C—H...O(nitro) and π–π stacking between benzene rings [inter-centroid separation = 3.5226 (10) Å]. Finally, double-layers parallel to (100) sustained by charge-assisted ammonium-N—H...O(carboxylate), ammonium-N—H...O(hydroxy) and hydroxy-O—H...O(carboxylate) hydrogen-bonds are apparent in the crystal of (III). These are connected in a three-dimensional architecture by amine-N—H...O(nitro) hydrogen-bonds.

Alkylammonium-chloroantimonate(III) Struktur und Schwingungsspektren/Alkylammoniumchloroantimonates(III). Structure and Vibrational Spectra

1983 ◽  
Vol 38 (2) ◽  
pp. 149-154 ◽  
Author(s):  
U. Ensinger ◽  
W. Schwarz ◽  
A. Schmidt
Keyword(s):  
Hydrogen Bonds ◽  
Vibrational Spectra ◽  
Molecular Structures ◽  
X Ray ◽  
Pyramidal Structure ◽  
Crystal And Molecular Structures ◽  
Tetragonal Pyramidal ◽  
Cl Atoms

Abstract The crystal and molecular structures of triethylammonium tetrachloroantimonate(III) (1) and tris[methylammonium] hexachloroantimonate(III) (2) were determined by X-ray analysis. In compound 1, SbCl3 molecules are bridged by Cl ions to form chains. The coordination of Sb by Cl atoms yields a distorted tetragonal-pyramidal structure. In compound 2 there are chains of SbCL4- ions, again through bridging by Cl ions. One Cl ion has no contacts to Sb. The cations of 1 and 2 form hydrogen bonds with the anionic components.

scholarly journals The 1:2 co-crystal formed between N,N′-bis(pyridin-4-ylmethyl)ethanediamide and benzoic acid: crystal structure, Hirshfeld surface analysis and computational study

2020 ◽  
Vol 76 (1) ◽  
pp. 102-110 ◽  
Author(s):  
Sang Loon Tan ◽  
Edward R. T. Tiekink
Keyword(s):  
Hydrogen Bonds ◽  
Benzoic Acid ◽  
Computational Study ◽  
Three Dimensional ◽  
Hirshfeld Surface ◽  
Molecular Structures ◽  
Amide Hydrogen ◽  
Title 1 ◽  
Crystal And Molecular Structures ◽  
Hirshfeld Surfaces

The crystal and molecular structures of the title 1:2 co-crystal, C14H14N4O2·2C7H6O2, are described. The oxalamide molecule has a (+)-antiperiplanar conformation with the 4-pyridyl residues lying to either side of the central, almost planar C2N2O2 chromophore (r.m.s. deviation = 0.0555 Å). The benzoic acid molecules have equivalent, close to planar conformations [C6/CO2 dihedral angle = 6.33 (14) and 3.43 (10)°]. The formation of hydroxy-O—H...N(pyridyl) hydrogen bonds between the benzoic acid molecules and the pyridyl residues of the diamide leads to a three-molecule aggregate. Centrosymmetrically related aggregates assemble into a six-molecule aggregate via amide-N—H...O(amide) hydrogen bonds through a 10-membered {...HNC2O}2 synthon. These are linked into a supramolecular tape via amide-N—H...O(carbonyl) hydrogen bonds and 22-membered {...HOCO...NC4NH}2 synthons. The contacts between tapes to consolidate the three-dimensional architecture are of the type methylene-C—H...O(amide) and pyridyl-C—H...O(carbonyl). These interactions are largely electrostatic in nature. Additional non-covalent contacts are identified from an analysis of the calculated Hirshfeld surfaces.

Monitoring structural transformations in crystals. 12. Course of an intramolecular [4 + 4] photocycloaddition in a crystal

2008 ◽  
Vol 64 (3) ◽  
pp. 375-382 ◽  
Author(s):  
Elżbieta Trzop ◽  
Ilona Turowska-Tyrk
Keyword(s):  
Hydrogen Bonds ◽  
Cell Volume ◽  
Molecular Shape ◽  
Structural Transformations ◽  
Photochemical Reactions ◽  
Molecular Structures ◽  
X Ray Diffraction ◽  
X Ray ◽  
Crystal And Molecular Structures ◽  
Orientation Of Molecules

Variations in crystal and molecular structures, brought about by the intramolecular [4 + 4] photocycloaddition of bi(anthracene-9,10-dimethylene), were monitored using X-ray diffraction. The cell volume increased by 0.8% until the reaction was ca 40% complete, and afterwards decreased by 1.6% during the remainder of the photoreaction. The changes of the a and b lattice parameters were correlated with the changes of the molecular shape and packing. The distance between the directly reacting C atoms varied in a manner not observed for other photochemical reactions in crystals. It was constant until ca 20% photoreaction progress, then decreased, and later stabilized from ca 40% photoreaction progress. This phenomenon was explained by interplay between stress resulting from the presence of product molecules and the rigidity of reactant molecules. Changes of the orientation of molecules during the photoreaction were smaller than in the case of other monitored photochemical reactions in crystals owing to similarities in the shape and packing of reactant and product molecules. Weak C—H...π hydrogen bonds exist among reactant molecules in the pure reactant and partly reacted crystals.

Crystal and molecular structures of spiro-3,4′-R-(3,3-dideoxy-1,2:5,6-di-O-isopropylidene-α-D-ribo-hexafuranose)-3′-S(and 3′-R)-acetamido-2′-pyrrolidone

1977 ◽  
Vol 55 (9) ◽  
pp. 1454-1462 ◽  
Author(s):  
Steven J. Rettig ◽  
James Trotter
Keyword(s):  
Hydrogen Bonds ◽  
Least Squares ◽  
Crystal Structures ◽  
Title Compound ◽  
Direct Methods ◽  
Molecular Structures ◽  
Full Matrix ◽  
Space Group ◽  
Crystal And Molecular Structures

Crystals of the 3′-S isomer of the title compound are orthorhombic, a = 23.004(5), b = 11.103(1), c = 7.616(3) Å, Z = 4, space group P212121. Crystals of the 3′-R isomer are orthorhombic, a = 24.898(1), b = 10.4122(4), c = 7.6467(6) Å, Z = 4, space group P212121. The structures were solved by direct methods and were refined by full-matrix least squares procedures to final R values of 0.038 for 1466 and 1996 reflections with I ≥ 3σ(I) for the 3′-S and 3′-R isomers respectively. Both crystal structures consist of discrete molecules linked by systems of intermolecular N—H … O hydrogen bonds and possible weak C—H … O interactions.

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