scholarly journals The Cyclobutanocucurbit[5–8]uril Family: Electronegative Cavities in Contrast to Classical Cucurbituril while the Electropositive Outer Surface Acts as a Crystal Packing Driver

Molecules ◽  
2021 ◽  
Vol 26 (23) ◽  
pp. 7343
Author(s):  
Minghua Chen ◽  
Naixia Lv ◽  
Weiwei Zhao ◽  
Anthony I. Day
Keyword(s):  
Single Crystal ◽  
Electrostatic Potential ◽  
Outer Surface ◽  
Crystal Packing ◽  
Structural Parameters ◽  
Near Neighbor ◽  
X Ray Diffraction ◽  
X Ray ◽  
Dipole Interactions

The structural parameters for the cyclobutanoQ[5–8] family were determined through single crystal X-ray diffraction. It was found that the electropositive cyclobutano methylene protons (CH2) are important in forming interlinking crystal packing arrangements driven by the dipole–dipole interactions between these protons and the portal carbonyl O of a near neighbor. This type of interaction was observed across the whole family. Electrostatic potential maps also confirmed the electropositive nature of the cyclobutano CH2 but, more importantly, it was established that the cavities are electronegative in contrast to classical Q[5–8], which are near neutral.

scholarly journals Accurate H-atom parameters for the two polymorphs of L-histidine at 5, 105 and 295 K

2021 ◽  
Vol 77 (5) ◽  
pp. 785-800
Author(s):  
Giulia Novelli ◽  
Charles J. McMonagle ◽  
Florian Kleemiss ◽  
Michael Probert ◽  
Horst Puschmann ◽  
...  
Keyword(s):  
Neutron Diffraction ◽  
Single Crystal ◽  
Diffraction Data ◽  
Crystal Packing ◽  
Basis Sets ◽  
X Ray Diffraction ◽  
X Ray ◽  
Refinement Method ◽  
Primary Amino ◽  
Precision And Accuracy

The crystal structure of the monoclinic polymorph of the primary amino acid L-histidine has been determined for the first time by single-crystal neutron diffraction, while that of the orthorhombic polymorph has been reinvestigated with an untwinned crystal, improving the experimental precision and accuracy. For each polymorph, neutron diffraction data were collected at 5, 105 and 295 K. Single-crystal X-ray diffraction experiments were also performed at the same temperatures. The two polymorphs, whose crystal packing is interpreted by intermolecular interaction energies calculated using the Pixel method, show differences in the energy and geometry of the hydrogen bond formed along the c direction. Taking advantage of the X-ray diffraction data collected at 5 K, the precision and accuracy of the new Hirshfeld atom refinement method implemented in NoSpherA2 were probed choosing various settings of the functionals and basis sets, together with the use of explicit clusters of molecules and enhanced rigid-body restraints for H atoms. Equivalent atomic coordinates and anisotropic displacement parameters were compared and found to agree well with those obtained from the corresponding neutron structural models.

Study on Novel Structure of Praseodymium Complex, C5H13O11Pr

2013 ◽  
Vol 834-836 ◽  
pp. 515-518
Author(s):  
Hai Xing Liu ◽  
Qing Liu ◽  
Ting Ting Huang ◽  
Yang Xu ◽  
Lin Tong Wang ◽  
...  
Keyword(s):  
Crystal Structure ◽  
Hydrogen Bonding ◽  
Single Crystal ◽  
Hydrothermal Reaction ◽  
Crystal Packing ◽  
X Ray Diffraction ◽  
X Ray ◽  
Hydrogen Bonding Interactions ◽  
Novel Structure ◽  
Praseodymium Complex

A novel praseodymium complex C5H13O11Pr has been synthesized from hydrothermal reaction and the crystal structure has been determined by means of single-crystal X-ray diffraction. The Pr1 atom is nine coordinated by nine O atoms. The crystal packing is stabilized by O-H...O hydrogen bonding interactions.

Synthesis, growth, structure and characterization of molybdenum zinc thiourea complex crystals

2015 ◽  
Vol 71 (3) ◽  
pp. 285-292 ◽  
Author(s):  
M. Rajasekar ◽  
K. Muthu ◽  
A. Aditya Prasad ◽  
R. Agilandeshwari ◽  
SP Meenakshisundaram
Keyword(s):  
Single Crystal ◽  
Diffraction Analysis ◽  
Intermolecular Interactions ◽  
Crystal Packing ◽  
Second Harmonic ◽  
Morphological Changes ◽  
Strong Interactions ◽  
X Ray Diffraction ◽  
X Ray ◽  
Cell Parameters

Single crystals of molybdenum-incorporated tris(thiourea)zinc(II) sulfate (MoZTS) are grown by the slow evaporation solution growth technique. Crystal composition as determined by single-crystal X-ray diffraction analysis reveals that it belongs to the orthorhombic system with space groupPca21and cell parametersa= 11.153 (2),b= 7.7691 (14),c= 15.408 (3) Å,V= 1335.14 (4) Å3andZ= 4. The surface morphological changes are studied by scanning electron microscopy. The vibrational patterns in FT–IR are used to identify the functional group and TGA/DTA (thermogravimetric analysis/differential thermal analysis) indicates the stability of the material. The structure and the crystallinity of the material were confirmed by powder X-ray diffraction analysis and the simulated X-ray diffraction (XRD) closely matches the experimental one with varied intensity patterns. The band gap energy is estimated using diffuse reflectance data by the application of the Kubelka–Munk algorithm. The relative second harmonic generation (SHG) efficiency measurements reveal that MoZTS has an efficiency comparable to that of tris(thiourea)zinc(II) sulfate (ZTS). Hirshfeld surfaces were derived using single-crystal X-ray diffraction data. Investigation of the intermolecular interactions and crystal packingviaHirshfeld surface analysis reveal that the close contacts are associated with strong interactions. Intermolecular interactions as revealed by the fingerprint plot and close packing could be the possible reasons for facile charge transfer leading to SHG activity.

scholarly journals Synthesis, Crystal Structure, and DFT Calculations of 1,3-Diisobutyl Thiourea

2015 ◽  
Vol 2015 ◽  
pp. 1-5 ◽  
Author(s):  
Ataf A. Altaf ◽  
Adnan Shahzad ◽  
Zarif Gul ◽  
Sher A. Khan ◽  
Amin Badshah ◽  
...  
Keyword(s):  
Crystal Structure ◽  
Hydrogen Bonding ◽  
Dft Calculations ◽  
Single Crystal ◽  
Crystal Packing ◽  
X Ray Diffraction ◽  
X Ray ◽  
Cell Dimensions ◽  
Unit Cell Dimensions ◽  
Model Support

1,3-Diisobutyl thiourea was synthesized and characterized by single crystal X-ray diffraction. It gives a monoclinic (α=γ= 90 andβ  ≠90) structure with the space group P21/c. The unit cell dimensions area= 11.5131 (4) Å,b= 9.2355 (3) Å,c= 11.3093 (5) Å,α= 90°,β= 99.569° (2),γ= 90°,V= 1185.78 (8) Å3, andZ= 4. The crystal packing is stabilized by intermolecular (N–H⋯S) hydrogen bonding in the molecules. The optimized geometry and Mullikan's charges of the said molecule calculated with the help of DFT using B3LYP-6-311G model support the crystal structure.

scholarly journals A 1:1 energetic co-crystal formed between trinitrotoluene and 2,3-diaminotoluene

2018 ◽  
Vol 37 (1) ◽  
pp. 61 ◽  
Author(s):  
Nilgun Sen
Keyword(s):  
Single Crystal ◽  
Intermolecular Interactions ◽  
Crystal Packing ◽  
Main Mechanism ◽  
Oxygen Balance ◽  
X Ray Diffraction ◽  
X Ray ◽  
Fingerprint Plots ◽  
Hirshfeld Surfaces ◽  
Π Stacking

A 1:1 co-crystal of trinitrotoluene (TNT) and 2,3-diaminotoluene was prepared by solvent evapo- ration, and the structure of the co-crystal was determined by single-crystal and powder X-ray diffraction. The results indicate that the main mechanism of co-crystallization originates from the intermolecular hy- drogen bonding (amino-nitro) and π-π stacking. We also examined the Hirshfeld surfaces and associated fingerprint plots of the co-crystal and reveal that the structures are stabilized by H…H, O–H, O…O and C…C (π-π) intermolecular interactions. We analyzed the crystal packing and show its influence upon im- pact sensitivity. The results highlight that co-crystallization is an effective way to modify the sensitivity, oxygen balance and density of explosives. 

scholarly journals Zirconium tetrachloride revisited

2018 ◽  
Vol 74 (3) ◽  
pp. 307-311
Author(s):  
Rosendo Borjas Nevarez ◽  
Samundeeswari Mariappan Balasekaran ◽  
Eunja Kim ◽  
Philippe Weck ◽  
Frederic Poineau
Keyword(s):  
Phase Transformation ◽  
Single Crystal ◽  
Structural Parameters ◽  
X Ray Diffraction ◽  
Zirconium Tetrachloride ◽  
Orthorhombic Space Group ◽  
Space Group ◽  
X Ray ◽  
Temperature Range ◽  
Crystallographic Study

Zirconium tetrachloride, ZrCl4, is a strategic material with wide-ranging applications. Until now, only one crystallographic study on ZrCl4has been reported [Krebs (1970).Z. Anorg. Allg. Chem.378, 263–272] and that was more than 40 years ago. The compound used for the previous determination was prepared from ZrO2and Cl2–CCl4, and single-crystal X-ray diffraction (SCXRD) studies on ZrCl4obtained from Zr metal have not yet been reported. In this context, we prepared ZrCl4from the reaction of Zr metal and Cl2gas in a sealed tube and investigated its structure at 100, 150, 200, 250, and 300 K. At 300 K, the SCXRD analysis indicates that ZrCl4crystallizes in the orthorhombic space groupPca21[a= 6.262 (9),b= 7.402 (11),c= 12.039 (17) Å, andV= 558.0 (14) Å3] and consists of infinite zigzag chains of edge-sharing ZrCl6octahedra. This chain motif is similar to that observed previously in ZrCl4, but the structural parameters and space group differ. In the temperature range 100–300 K, no phase transformation was identified, while elongation of intra-chain Zr...Zr [3.950 (1) Å at 100 K and 3.968 (5) Å at 300 K] and inter-chain Cl...Cl [3.630 (3) Å at 100 K and 3.687 (9) Å at 300 K] distances occurred.

Crystal structure of methyl 8-Iodo-4,5,7-trimethoxy-2-naphthoate

1977 ◽  
Vol 30 (10) ◽  
pp. 2313 ◽  
Author(s):  
DW Cameron ◽  
GI Feutrill ◽  
vB Lammerts ◽  
CL Raston ◽  
AH White
Keyword(s):  
Crystal Structure ◽  
Single Crystal ◽  
Least Squares ◽  
Title Compound ◽  
Crystal Packing ◽  
Molecular Geometry ◽  
X Ray Diffraction ◽  
X Ray

The crystal structure of the title compound, C15H15IO5, has been determined by single crystal X-ray diffraction at 295 K and refined by least squares to a residual of 0.04 (2210 ?observed? reflections). Crystals are monoclinic, P21/c, a 10.294(5), b 18.868(9), c 7.549(6) Ǻ, β 90.29(5)�, Z 4. The molecular geometry apart from the iodine environment is as expected; the crystal packing is such that the iodine lies close to a symmetry-related neighbour at I...I 4.148(2) Ǻ and may account for the observed facile elimination of iodine from the solid on heating to 120�C.

Crystal structure of dunnione p-bromophenylhydrazone

1980 ◽  
Vol 33 (2) ◽  
pp. 441 ◽  
Author(s):  
RG Cooke ◽  
CL Raston ◽  
AH White
Keyword(s):  
Crystal Structure ◽  
Charge Transfer ◽  
Single Crystal ◽  
Crystal Packing ◽  
X Ray Diffraction ◽  
X Ray ◽  
Intermolecular Charge Transfer

The crystal structure of dunnione p-bromophenylhydrazone has been determined by single-crystal X-ray diffraction methods at 295 K, the structure being refined to a residual of 0.054 for 1429 'observed' reflections. Crystals are triclinic, Pī, a 15.620(8), b 8.804(4), c 7.439(4) Ǻ, α 68.03(4), β 89.85(4), γ 77.44(4)°, Z 2. The conjugation throughout the molecule is extensive and the crystal packing is dominated by intermolecular charge-transfer interactions. Bonding in the hydrazone moiety lies intermediate between those expected for hydrazone and azo forms.

Comparison of the crystal structures and physicochemical properties of novel resveratrol cocrystals

2019 ◽  
Vol 75 (6) ◽  
pp. 1186-1196 ◽  
Author(s):  
Bo Peng ◽  
Hongyan He ◽  
Meiqi Li ◽  
Jian-Rong Wang ◽  
Xuefeng Mei
Keyword(s):  
Physicochemical Properties ◽  
Single Crystal ◽  
Crystal Packing ◽  
Biological Activities ◽  
Heating Process ◽  
Valuable Insight ◽  
X Ray Diffraction ◽  
Dynamic Vapor Sorption ◽  
Buffer Solution ◽  
X Ray

Resveratrol (RSV) is one of the most extensively investigated natural polyphenol with potential cardioprotective effects and various biological activities. However, the polymorphism and solvates of RSV cocrystals have not been studied comprehensively. In addition, the relationship between the crystal packing modes and their physicochemical properties of RSV cocrystals remains poorly understood. In this paper, seven novel RSV cocrystals were prepared and characterized by powder X-ray diffraction, single-crystal X-ray diffraction, thermogravimetric analysis, differential scanning calorimetry, dynamic vapor sorption, Raman and Fourier transform infrared spectroscopy. Five RSV–4,4′-vinylenedipyridine (DPE) cocrystals were synthesized with polymorphs and solvates, such as RSV–DPE (1:2) in form (I) [RSV–2DPE form (I)], RSV–DPE (1:2) in form (II) [RSV–2DPE form (II)], RSV–DPE (1:1) (RSV–DPE), RSV–DPE (2:3)·acetone (RSV–1.5DPE·0.5ACE), RSV–DPE (1:1.5)·MeOH (RSV–1.5DPE·MeOH). However, RSV–4,4′-ethylenedipyridine (BPE) and RSV–4,4′-azobispyridine (AZPY) cocrystals were prepared as their single crystal forms, that is, RSV–BPE (1:1.5) (RSV–1.5BPE) and RSV–AZPY (1:2) (RSV–2AZPY). RSV–2DPE form (II) can be transformed from RSV–2DPE form (I) during the heating process from single crystal to single crystal. The physicochemical properties of RSV cocrystals are closely related to their crystal packing modes. Also, the conformation and molecular packing of RSV among different cocrystals is flexible. The solubility of RSV–1.5BPE and RSV–2DPE form (II) exhibit higher than RSV in the buffer solution of pH 4.6 and 2.0, respectively. This study may provide a valuable insight into the crystal packing modes of cocrystals which may affect their physicochemical properties.

scholarly journals Synthesis, crystal structure and study of the crystal packing in the complex bis(4-aminopyridine-κN 1)dichloridocobalt(II)

2017 ◽  
Vol 73 (5) ◽  
pp. 399-406 ◽  
Author(s):  
Olga Carolina Sanchez Montilva ◽  
Federico Movilla ◽  
Maricel Gabriela Rodriguez ◽  
Florencia Di Salvo
Keyword(s):  
Crystal Structure ◽  
Single Crystal ◽  
Crystal Packing ◽  
Three Dimensional ◽  
Spectroscopic Techniques ◽  
X Ray Diffraction ◽  
X Ray ◽  
Π Interactions ◽  
Structures And Properties ◽  
Statistical Studies

Despite the large number of reported crystalline structures of coordination complexes bearing pyridines as ligands, the relevance of π–π interactions among these hereroaromatic systems in the stabilization of their supramolecular structures and properties is not very well documented in the recent literature. The title compound, [CoCl2(C5H6N2)2], was obtained as bright-blue crystals suitable for single-crystal X-ray diffraction analysis from the reaction of 4-aminopyridine with cobalt(II) chloride in ethanol. The new complex was fully characterized by a variety of spectroscopic techniques and single-crystal X-ray diffraction. The crystal structure showed a tetrahedral complex stabilized mainly by bidimensional motifs constructed by π–π interactions with large horizontal displacements between the 4-aminopyridine units, and N—H...Cl hydrogen bonds. Other short contacts, such as C—H...Cl interactions, complete the three-dimensional arrangement. The supramolecular investigation was extended by statistical studies using the Cambridge Structural Database and a Hirshfeld surface analysis.

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