Role of intermolecular hydrogen-bonding in the crystal structure of α-chloroacetic acid

1976 ◽  
pp. 715-716 ◽  
Author(s):  
B. Kalyanaraman ◽  
J. L. Atwood ◽  
L. D. Kispert
Keyword(s):  
Crystal Structure ◽  
Hydrogen Bonding ◽  
Chloroacetic Acid ◽  
Intermolecular Hydrogen Bonding

scholarly journals Planarversusnon-planar: The important role of weak C—H...O hydrogen bonds in the crystal structure of 5-methylsalicylaldehyde

2017 ◽  
Vol 73 (2) ◽  
pp. 155-158 ◽  
Author(s):  
Ulrich Baisch ◽  
Marie Christine Scicluna ◽  
Christian Näther ◽  
Liana Vella-Zarb
Keyword(s):  
Crystal Structure ◽  
Hydrogen Bonding ◽  
Hydrogen Bonds ◽  
Aromatic Ring ◽  
Structural Changes ◽  
Intermolecular Hydrogen Bonding ◽  
Hydrogen Atoms ◽  
Methyl Carbon ◽  
Distorted Geometry

The crystal structure of 5-methylsalicylaldehyde (5-MSA; systematic name 2-hydroxy-5-methylbenzaldehyde), C8H8O2, was discovered to be a textbook example of the drastic structural changes caused by just a few weak C—H...O interactions due to the additional methylation of the aromatic ring compared to salicylaldehydeSA. This weak intermolecular hydrogen bonding is observed between aromatic or methyl carbon donor atoms and hydroxyl or aldehyde acceptor oxygen atoms withd(D...A) = 3.4801 (18) and 3.499 (11) Å. The molecule shows a distorted geometry of the aromatic ring with elongated bonds in the vicinity of substituted aldehyde and hydroxyl carbon atoms. The methyl hydrogen atoms are disordered over two sets of sites with occupancies of 0.69 (2) and 0.31 (2).

scholarly journals Exploring the Structural Chemistry of Pyrophosphoramides: N,N′,N″,N‴-Tetraisopropylpyrophosphoramide

Chemistry ◽  
2021 ◽  
Vol 3 (1) ◽  
pp. 149-163
Author(s):  
Duncan Micallef ◽  
Liana Vella-Zarb ◽  
Ulrich Baisch
Keyword(s):  
Crystal Structure ◽  
Mass Spectrometry ◽  
Nuclear Magnetic Resonance ◽  
Hydrogen Bonding ◽  
Nmr Spectroscopy ◽  
Ir Spectroscopy ◽  
Room Temperature ◽  
Intermolecular Hydrogen Bonding ◽  
X Ray Diffraction ◽  
X Ray

N,N′,N″,N‴-Tetraisopropylpyrophosphoramide 1 is a pyrophosphoramide with documented butyrylcholinesterase inhibition, a property shared with the more widely studied octamethylphosphoramide (Schradan). Unlike Schradan, 1 is a solid at room temperature making it one of a few known pyrophosphoramide solids. The crystal structure of 1 was determined by single-crystal X-ray diffraction and compared with that of other previously described solid pyrophosphoramides. The pyrophosphoramide discussed in this study was synthesised by reacting iso-propyl amine with pyrophosphoryl tetrachloride under anhydrous conditions. A unique supramolecular motif was observed when compared with previously published pyrophosphoramide structures having two different intermolecular hydrogen bonding synthons. Furthermore, the potential of a wider variety of supramolecular structures in which similar pyrophosphoramides can crystallise was recognised. Proton (1H) and Phosphorus 31 (31P) Nuclear Magnetic Resonance (NMR) spectroscopy, infrared (IR) spectroscopy, mass spectrometry (MS) were carried out to complete the analysis of the compound.

scholarly journals Crystal structure of a trigonal polymorph of aquadioxidobis(pentane-2,4-dionato-κ2 O,O′)uranium(VI)

2022 ◽  
Vol 78 (1) ◽  
Author(s):  
Alejandro Hernandez ◽  
Indranil Chakraborty ◽  
Gabriela Ortega ◽  
Christopher J. Dares
Keyword(s):  
Crystal Structure ◽  
Hydrogen Bonding ◽  
Water Molecule ◽  
Equatorial Plane ◽  
Title Compound ◽  
Uranium Atom ◽  
Intermolecular Hydrogen Bonding ◽  
Two Dimensional ◽  
Asymmetric Unit ◽  
Acta Cryst

The title compound, [UO2(acac)2(H2O)] consists of a uranyl(VI) unit ([O=U=O]2+) coordinated to two monoanionic acetylacetonate (acac, C5H7O2) ligands and one water molecule. The asymmetric unit includes a one-half of a uranium atom, one oxido ion, one-half of a water molecule and one acac ligand. The coordination about the uranium atom is distorted pentagonal–bipyramidal. The acac ligands and Ow atom comprise the equatorial plane, while the uranyl O atoms occupy the axial positions. Intermolecular hydrogen bonding between complexes results in the formation of two-dimensional hexagonal void channels along the c-axis direction with a diameter of 6.7 Å. The monoclinic (P21/c space group) polymorph was reported by Alcock & Flanders [(1987). Acta Cryst. C43, 1480–1483].

Synthese, Struktur und thermisches Verhalten von Thiophosphorsäuretriamid SP(NH2)3 [1] / Synthesis, Structure, and Thermal Behaviour of Phosphorothionic Triamide SP(ΝΗ2)3 [1]

1989 ◽  
Vol 44 (8) ◽  
pp. 942-945 ◽  
Author(s):  
Wolfgang Schnick
Keyword(s):  
Crystal Structure ◽  
Hydrogen Bonding ◽  
Thermal Properties ◽  
Single Crystal ◽  
Melting Temperature ◽  
Intermolecular Hydrogen Bonding ◽  
X Ray ◽  
Hydrogen Bonding Interactions ◽  
Ray Methods ◽  
Single Bonds

Phosphorothionic triamide SP(NH2)3 is obtained by slow addition of SPCl3 dissolved in dry CH2Cl2 to a satured solution of NH3 in CH2Cl2 at —50°C. Ammonium chloride is removed from the resulting precipitate by treatment with HNEt2 followed by extraction with CH2Cl2. Coarse crystalline SP(NH2)3 is obtained after recrystallization from dry methanol. The crystal structure of SP(NH2)3 has been determined by single crystal X-ray methods (Pbca; a = 922.3(1), b = 953.8(1), c = 1058.4(2) pm, Z = 8). In the crystals the molecules show non-crystallographic point symmetry C8. The P—S bond (195.4(1) pm) is slightly longer than in SPCl3. From P—N bond lengths of about 166 pm a significant electrostatic strengthening of the P—N single bonds is assumed. Weak intermolecular hydrogen bonding interactions (N —H · · · N ≥ 329.5 pm; N — H · · · S ≥ 348.3 pm) are observed.Investigation of thermal properties shows a melting temperature of 115°C for SP(NH2)3. According to combined DTA/TG and MS investigations above this temperature the compound decomposes by evolution of H2S and NH3 to yield amorphous phosphorus(V)nitride.

7α-Acetoxydihydronomilin: isolation, spectra, and crystal structure

1978 ◽  
Vol 56 (7) ◽  
pp. 1020-1025 ◽  
Author(s):  
Farid R. Ahmed ◽  
Angs Ng ◽  
Alex G. Fallis
Keyword(s):  
Crystal Structure ◽  
Hydrogen Bonding ◽  
Least Squares ◽  
Furan Ring ◽  
Lactone Ring ◽  
Direct Method ◽  
Membered Ring ◽  
Intermolecular Hydrogen Bonding ◽  
X Ray ◽  
Twist Boat

Methanol extraction of the ground seeds of Uncaria Gambier Roxb. followed by chromatography afforded a crystalline C30H38O10 terpene. This has been shown by X-ray analysis to be 7α-acetoxydihydronomilin. The crystals are orthorhombic, P212121, a = 13.158(2), b = 17.092(2), c = 12.689(2) Å, Z = 4, dx = 1.300, do = 1.300 g cm−3. The structure has been determined by the direct method and Fourier syntheses, and refined by block-diagonal least-squares to R = 0.042 for 2621 observed reflexions. The molecule contains a seven-membered lactone ring A, three six-membered rings B, C, D, a three-membered ring E, a furan ring F, and two acetate groups. A and B are chair, C is twist-boat, D is 1,3-diplanar, while E and F are planar. The A/B, A/C, C/D junctions are trans, D/E is cis, and F is linked to D by an equatorial C—C bond. The two acetate groups are in axial positions on A and B and are cis to each other. The O atom forming the apex of the three-membered ring is wedged between two H atoms and their parent C atoms at short intramolecular distances O … H = 2.28(2) and 2.28(3), and O … C = 2.623(3) and 2.668(4) Å. No intermolecular hydrogen bonding is indicated.

(2R,3S,4S,5R)-4-Hydroxy-3-iodo-5-methyltetrahydro-2-furylmethyl benzoate

2000 ◽  
Vol 57 (1) ◽  
pp. o58-o60
Author(s):  
Sean P. Bew ◽  
Mark E. Light ◽  
Michael B. Hursthouse ◽  
David W. Knight ◽  
Robert J. Middleton
Keyword(s):  
Crystal Structure ◽  
Hydrogen Bonding ◽  
Structure Determination ◽  
Title Compound ◽  
Crystal Structure Determination ◽  
Intermolecular Hydrogen Bonding ◽  
Compound C ◽  
Relative Stereochemistry

The crystal structure determination of the title compound, C13H15IO4, has allowed the relative stereochemistry between the tetrasubstituted C atoms on the tetrahydrofuran moiety to be confirmed. The title compound is a precursor of the ionophoric antibiotic Aplasmomycin. The compound is involved in both intra- and intermolecular hydrogen bonding, the latter link the molecules into chains running along thebaxis.

A heterotrimetallic Ni(II)–Dy(III) bis(salamo)-based complex: synthesis, structure and fluorescent property

2018 ◽  
Vol 73 (5) ◽  
pp. 281-288
Author(s):  
Qing Zhao ◽  
Ying-Qi Pan ◽  
Xiao-Yan Li ◽  
Han Zhang ◽  
Wen-Kui Dong
Keyword(s):  
Crystal Structure ◽  
Hydrogen Bonding ◽  
Supramolecular Structure ◽  
Fluorescence Spectra ◽  
Intermolecular Hydrogen Bonding ◽  
X Ray Diffraction ◽  
X Ray ◽  
Distorted Octahedral ◽  
Tricapped Trigonal Prism ◽  
Elemental Analyses

AbstractA discrete heterotrinuclear complex [{Ni2LDy(OAc)3(CH3OH)}2] · 2CH3OH · 3CH2Cl2, with a naphthalenediol-based acyclic bis(salamo) ligand H4L, has been synthesized and structurally characterized using elemental analyses, IR, UV/Vis and fluorescence spectra and single crystal X-ray diffraction. The crystal structure shows two crystallographically independent but chemically identical molecules (molecules I and II). All the Ni(II) atoms are hexa-coordinated with slightly distorted octahedral geometries. The central Dy atoms are nona-coordinated with slightly distorted tricapped trigonal prism geometries. An infinite 3D supramolecular structure is formed via intermolecular hydrogen bonding and C–H…π interactions.

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