scholarly journals The crystal structures and mechanical properties of the uranyl carbonate minerals roubaultite, fontanite, sharpite, widenmannite, grimselite and čejkaite

2020 ◽  
Vol 7 (21) ◽  
pp. 4197-4221 ◽  
Author(s):  
Francisco Colmenero ◽  
Jakub Plášil ◽  
Jiří Sejkora
Keyword(s):  
Mechanical Properties ◽  
Hydrogen Bonding ◽  
Diffraction Pattern ◽  
Crystal Structures ◽  
First Principles ◽  
X Ray Diffraction ◽  
Carbonate Minerals ◽  
X Ray ◽  
Uranyl Carbonate

The structure, hydrogen bonding, X-ray diffraction pattern and mechanical properties of six important uranyl carbonate minerals, roubaultite, fontanite, sharpite, widenmannite, grimselite and čejkaite, are determined using first principles methods.

scholarly journals Structures of (S)-(−)-4-oxo-2-azetidinecarboxylic acid and 3-azetidinecarboxylic acid from powder synchrotron diffraction data

2006 ◽  
Vol 62 (4) ◽  
pp. 606-611 ◽  
Author(s):  
Asiloé J. Mora ◽  
Michela Brunelli ◽  
Andrew N. Fitch ◽  
Jonathan Wright ◽  
Maria E. Báez ◽  
...  
Keyword(s):  
Hydrogen Bonding ◽  
Crystal Structures ◽  
Diffraction Data ◽  
Direct Methods ◽  
X Ray Diffraction ◽  
Synchrotron Diffraction ◽  
X Ray ◽  
The Asymmetry

The crystal structures of the four-membered heterocycles (S)-(−)-4-oxo-2-azetidinecarboxylic acid (I) and 3-azetidinecarboxylic acid (II) were solved by direct methods using powder synchrotron X-ray diffraction data. The asymmetry of the oxoazetidine and azetidine rings is discussed, along with the hydrogen bonding.

Inhibitors of the geotropic response in plants. The crystal structures of 2-[(Naphthalen-2-yl)carbamoyl]benzoic acid (β-Naptalam), 2-(Phenylcarbamoyl)-benzoic acid and 2-(5-Phenyl-1,3,4-oxadiazol-2-yl)benzoic acid

1983 ◽  
Vol 36 (12) ◽  
pp. 2455 ◽  
Author(s):  
G Smith ◽  
CHL Kennard ◽  
GF Katekar
Keyword(s):  
Hydrogen Bonding ◽  
Carboxylic Acid ◽  
Benzoic Acid ◽  
Crystal Structures ◽  
Carboxylic Acids ◽  
Intermolecular Hydrogen Bonding ◽  
X Ray Diffraction ◽  
X Ray ◽  
Carboxylic Acid Groups ◽  
Phthalamic Acid

The crystal structures of three geotropically active phthalamic acid derivatives have been determined by means of X-ray diffraction and the structural systematics for the series compared. The three acids are conformationally similar and, in contrast to the tendency among carboxylic acids to form hydrogen-bonded dimers, they exist as monomers with intermolecular hydrogen bonding between the carboxylic acid groups and the nitrogen or oxygen of the amide side chains.

scholarly journals Two metal–organic frameworks based on Sr2+ and 1,2,4,5-tetrakis(4-carboxyphenyl)benzene linkers

2021 ◽  
Vol 77 (12) ◽  
Author(s):  
Muhammad Usman ◽  
Lydia Ogebule ◽  
Raúl Castañeda ◽  
Evgenii Oskolkov ◽  
Tatiana Timofeeva
Keyword(s):  
Hydrogen Bonding ◽  
Single Crystal ◽  
Crystal Structures ◽  
Structural Control ◽  
Metal Organic Frameworks ◽  
X Ray Diffraction ◽  
X Ray ◽  
Metal Organic ◽  
Solvent Systems ◽  
Semiconductor Properties

Two structurally different metal–organic frameworks based on Sr2+ ions and 1,2,4,5-tetrakis(4-carboxyphenyl)benzene linkers have been synthesized solvothermally in different solvent systems and studied with single-crystal X-ray diffraction technique. These are poly[[μ12-4,4′,4′′,4′′′-(benzene-1,2,4,5-tetrayl)tetrabenzoato](dimethylformamide)distrontium(II)], [Sr2(C34H18O8)(C3H7NO)2] n , and poly[tetraaqua{μ2-4,4′-[4,5-bis(4-carboxyphenyl)benzene-1,2-diyl]dibenzoato}tristrontium(II)], [Sr3(C34H20O8)2(H2O)4]. The differences are noted between the crystal structures and coordination modes of these two MOFs, which are responsible for their semiconductor properties, where structural control over the bandgap is desirable. Hydrogen bonding is present in only one of the compounds, suggesting it has a slightly higher structural stability.

scholarly journals Crystal structures of (E)-1-naphthaldehyde oxime and (E)-phenanthrene-9-carbaldehyde oxime

2018 ◽  
Vol 74 (3) ◽  
pp. 332-336
Author(s):  
Jamal Lasri ◽  
Katherine Chulvi ◽  
Naser Eltaher Eltayeb
Keyword(s):  
Hydrogen Bonding ◽  
Crystal Structures ◽  
Hydroxylamine Hydrochloride ◽  
Dihedral Angles ◽  
Hydrogen Bonding Interaction ◽  
X Ray Diffraction ◽  
One Dimensional ◽  
X Ray ◽  
Bonding Interaction ◽  
Polymeric Chains

The aldoximes C11H9NO (I) and C15H11NO (II), synthesized inca90% yield, by treatment of 1-naphthaldehyde or phenanthrene-9-carbaldehyde, respectively, with hydroxylamine hydrochloride and sodium carbonate, have been characterized by IR,1H,13C and DEPT-135 NMR spectroscopies, and also by single-crystal X-ray diffraction analysis. The molecules of (I) and (II) are conformationally similar, with the aldoxime substituent groups lying outside the planes of the naphthalene or phenanthrene rings, forming dihedral angles with them of 23.9 (4) and 27.9 (6)°, respectively. The crystal structures of both (I) and (II) are similar with a single intermolecular O—H...N hydrogen-bonding interaction, giving rise to the formation of one-dimensional polymeric chains extending along the 21(b) screw axes in each.

Crystal chemistry of some synthetic 2-oxa-steroids: conformation, packing motifs and isostructurality

2000 ◽  
Vol 56 (3) ◽  
pp. 512-525 ◽  
Author(s):  
Addlagatta Anthony ◽  
Mariusz Jaskólski ◽  
Ashwini Nangia
Keyword(s):  
Hydrogen Bonding ◽  
Crystal Structures ◽  
Lactone Ring ◽  
X Ray Diffraction ◽  
Binary Solid Solution ◽  
Anabolic Agent ◽  
X Ray ◽  
Lactone Carbonyl ◽  
Chemical Factors ◽  
Methylene Group

The crystal structures of six synthetic 2-oxa-steroids (A-ring lactone steroids) have been determined by single-crystal X-ray diffraction. The conformation and hydrogen bonding in these oxa-steroids is compared with packing motifs in the natural steroids and the anabolic agent, Anavar®. O—H...O hydrogen bonding with lactone carbonyl O is the preferred arrangement in molecules with a C—OH group. The donor H atoms of A, B and D rings participate in C—H...O interactions with lactone carbonyl O and D-ring hydroxyl/ketone O acceptor atoms. The conformation of the lactone ring in these analogues is different from the natural androgens because replacement of the C2-methylene group by an O atom changes the geometry of the A ring. Two structurally related lactone steroids provide the first example of O—H...O/C—H...O interaction mimicry and furthermore the two components form a binary solid solution. The O—H...O and C—H...O hydrogen bonds in 2-oxa-steroid crystal structures are analysed and the observed preferences discussed in terms of geometric and chemical factors.

scholarly journals Bonding effects and the crystal structures of (NH4)2[Cu(H2O)6](SO4)2 and its H2 18O substituted form at 9.5 K

2000 ◽  
Vol 56 (3) ◽  
pp. 438-443 ◽  
Author(s):  
Brian N. Figgis ◽  
Alexandre N. Sobolev ◽  
Charles J. Simmons ◽  
Michael A. Hitchman ◽  
Horst Stratemeier ◽  
...  
Keyword(s):  
Hydrogen Bonding ◽  
Crystal Structures ◽  
X Ray Diffraction ◽  
Tutton Salts ◽  
X Ray ◽  
Distorted Octahedral ◽  
Structural Differences ◽  
Jahn Teller ◽  
Normal Water ◽  
Water Ligands

The crystal structures of the Tutton salts (NH4)2-[Cu(H2O)6](SO4)2, diammonium hexaaquacopper disulfate, formed with normal water and isotopically substituted H2 18O, have been determined by X-ray diffraction at 9.5 K and are very similar, with Cu—O(7) the longest of the Cu—O bonds of the Jahn–Teller distorted octahedral [Cu(H2O)6]2+ complex. It is known that structural differences accompany deuteration of (NH4)2[Cu(H2O)6](SO4)2, the most dramatic of which is a switch to Cu—O(8) as the longest such bond. The present result suggests that the structural differences are associated with hydrogen-bonding effects rather than with increased mass of the water ligands affecting the Jahn–Teller coupling. The Jahn–Teller distortions and hydrogen-bonding contacts in the compounds are compared with those reported for other Tutton salts at ambient and high pressure.

Application of Wallach's Rule in a Comparison of the X-ray Crystal Structures of the Racemate and the (S) Enantiomer of (1-Hydroxy-3-phenyl-2-propenyl) Dimethylphosphonate

1997 ◽  
Vol 53 (5) ◽  
pp. 838-842 ◽  
Author(s):  
V. J. Blazis ◽  
K. J. Koeller ◽  
N. P. Rath ◽  
C. D. Spilling
Keyword(s):  
Hydrogen Bonding ◽  
Crystal Structures ◽  
Atomic Displacement ◽  
X Ray Diffraction ◽  
X Ray ◽  
Crystal Density

The crystal structures of the racemate and the (S) enantiomer of (1-hydroxy-3-phenyl-2-propenyl) dimethylphosphonate, C11H15O4P, were determined by X-ray diffraction. The crystal density of the racemate was found to be 6.2% greater than the crystal density of the (S) enantiomer. In both crystal structures the molecules form chains by hydrogen bonding between the OH of one molecule and the P=O of another. Observed differences in atomic displacement between the two structures are discussed in view of the C—H...O interactions.

scholarly journals Crystal Structures of Two Macrocyclic Bischalcones Possessing 26-Membered Rings

2015 ◽  
Vol 2015 ◽  
pp. 1-5
Author(s):  
Rina Mondal ◽  
Nayim Sepay ◽  
Debajyoti Ghoshal ◽  
Asok K. Mallik
Keyword(s):  
Hydrogen Bonding ◽  
Single Crystal ◽  
Crystal Structures ◽  
Membered Ring ◽  
X Ray Diffraction ◽  
Monoclinic System ◽  
Triclinic Space Group ◽  
Space Group ◽  
X Ray ◽  
Hydrogen Bonding Interactions

Single crystal X-ray diffraction of two macrocyclic bischalcones, namely, (2E,25E)-11,17,33,37-tetraoxapentacyclo[36.4.0.05,10.018,23.027,32]dotetraconta-1(42),2,5,7,9,18,20,22,25,27,29,31,38,40-tetradecaene-4,24-dione(1) and (2E,24E)-11,16,32,37-tetraoxapentacyclo[36.4.0.05,10.017,22.026,31]dotetraconta-1(42),2,5,7,9,17,19,21,24,26,28,30,38,40-tetradecaene-4,23-dione(2), each containing a 26-membered ring, has been studied. Compound 1 belongs to the monoclinic system, space group C2/c with a = 34.3615(9) Å, b = 12.7995(3) Å, c = 14.6231(3) Å, β = 96.912(2)°,  V = 6,384.6(3) Å3, and Z = 8. Compound 2 is triclinic, space group P-1 with a = 10.066(2) Å, b = 10.670(3) Å, c = 16.590(3) Å, α = 85.95(2), β = 89.244(14), γ = 62.211(13), V = 1572.0(6) Å3, and Z = 2. Intermolecular C–H⋯O hydrogen bonding interactions are present in both compounds.

Growth Mechanism of Hollow ZnO Microsphere with Aperture Prepared by Oxidation of Zn Powder

2011 ◽  
Vol 117-119 ◽  
pp. 1260-1263
Author(s):  
Yuan Xing Li ◽  
Dong Hua Fan ◽  
Hui Ren Peng ◽  
Bo Jie Li
Keyword(s):  
High Pressure ◽  
Diffraction Pattern ◽  
Crystal Structures ◽  
Growth Mechanism ◽  
Thermal Evaporation ◽  
Hollow Microsphere ◽  
Gas Pressure ◽  
Experimental Results ◽  
X Ray Diffraction ◽  
X Ray

ZnO microsphere with aperture were synthesized using pure Zn powder as templates via thermal evaporation methods. X-ray diffraction pattern shows the change of crystal structures from Zn to ZnO. SEM and TEM images show that the samples prepared at low gas pressure have hollow ZnO microsphere with aperture. Compared with the morphologies of samples synthesized at high gas pressure, the growth mechanism of hollow ZnO microsphere with aperture is presumed in detail. The experimental results indicate that the evaporation of Zn inside the ZnO microsphere shell prompts the formation of hollow microsphere, and that the high pressure induces the breakage of weak locations to form the apertures, which eventually results in the appearance of ZnO microsphere with small pores and big apertures.

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