scholarly journals Structure and Physical Properties of Cardamonin: A Spectroscopic and Computational Approach

Molecules ◽  
2020 ◽  
Vol 25 (18) ◽  
pp. 4070 ◽  
Author(s):  
Iwona Budziak ◽  
Marta Arczewska ◽  
Daniel M. Kamiński
Keyword(s):  
Crystal Structure ◽  
Crystal Lattice ◽  
Density Functional ◽  
Xrd Analysis ◽  
Biological Properties ◽  
Molecular Structures ◽  
Functional Theory ◽  
Water Fractions ◽  
The Stability ◽  
Single Crystal Xrd Analysis

This is the first study of the crystal structure of cardamonin (CA) confirmed using single-crystal XRD analysis. In the crystal lattice of CA, two symmetry independent molecules are linked by hydrogen bonds within the layers and by the π···π stacking interactions in the columns which lead to the occurrence of two types of conformations among the CA molecules in the crystal structure. To better understand the stability of these arrangements in both crystals and the gaseous phase, seven different CA dimers were theoretically calculated. The molecular structures were optimized using density functional theory (DFT) at the B3LYP/6–311G+(d,p) level and the spectroscopic results were compared. It was found that the calculated configurations of dimer I and III were almost identical to the ones found in the CA crystal lattice. The calculated UV-Vis spectra for the CA monomer and dimer I were perfectly consistent with the experimental spectroscopic data. Furthermore, enhanced emissions induced by aggregated CA molecules were registered in the aqueous solution with the increase of water fractions. The obtained results will help to further understand the relation between a variety of conformations and the biological properties of CA, and the results are also promising in terms of the applicability of CA as a bioimaging probe to monitor biological processes.

scholarly journals Solid-State and Theoretical Investigations of Some Banister-Type Macrocycles with 2,2’-Aldoxime-1,1’-Biphenyl Units

2021 ◽  
Vol 9 ◽  
Author(s):  
Ioan Stroia ◽  
Ionuţ -Tudor Moraru ◽  
Maria Miclăuş ◽  
Ion Grosu ◽  
Claudia Lar ◽  
...  
Keyword(s):  
Crystal Structure ◽  
Solid State ◽  
Density Functional ◽  
Alkali Metal Ions ◽  
Functional Theory ◽  
State Data ◽  
Supramolecular Associations ◽  
Theoretical Investigations ◽  
The Stability ◽  
Good Agreement

In the context of helical chirality, bridging of biphenyl units leads to banister-type compounds and the stability of the resulted atropisomers may increase dramatically if suitable changes are performed in the linker unit that coils around the biphenyl moiety. A rigorous density functional theory (DFT) study was conducted for macrocycles containing rigid oxime ether segments connected to the biphenyl backbone in order to determine how the rotation barriers are influenced by the presence of either a flexible oligoethyleneoxide or a more rigid m–xylylene component in the macrocycle. The calculated values for the racemization barrier were in good agreement with those obtained experimentally and confirm the benefit of introducing a more rigid unit in the macrocycle on the stability of atropisomers. Solid-state data were obtained and computed data were used to assess the contribution brought by supramolecular associations observed in the lattice to the stabilization of the crystal structure. Beside introducing rigidity in the linker, complexation of flexible macrocycles with alkali metal ions is also contributing to the stability of atropisomers, leading to values for the racemization barrier matching that of the rigid macrocycle. Using diethylammonium cation as guest for the macrocycle, a spectacular increase in the barrier to rotation was observed for the resulted pseudo[2]rotaxane.

XRD Multi-Temperatures Study of N,N'-bis(2-Hydroxyethyl)Benzene-1,4-Dicarboxamide

2010 ◽  
Vol 163 ◽  
pp. 256-259
Author(s):  
Gabriela Bednarek ◽  
Maria Nowak ◽  
Joachim Kusz ◽  
Jerzy Ossowski
Keyword(s):  
Crystal Structure ◽  
Density Functional Theory ◽  
Dft Calculations ◽  
Chemical Reactions ◽  
Title Compound ◽  
Density Functional ◽  
Temperature Analysis ◽  
Functional Theory ◽  
X Ray ◽  
The Stability

N,N’ – bis – (2– hydroxy – ethylene) – terephthalamide (BHETA) has been obtained by aminolysis of polyethylene terephthalate (PET) using excess of monoethanoloamine and it has been physicochemically characterized [1]. In this paper there are shown the results of the multi-temperature X-ray measurement which were performed to provide information about the stability of the structure. Detailed temperature analysis of the crystal structure allows us to determine properties of the compound which is very important product of recycling PET wastes in order to use it for further chemical reactions. The structure of the title compound was also modelled by density functional theory (DFT) calculations.

scholarly journals Crystal structure, Hirshfeld surface analysis and DFT studies of 1,3-bis[2-methoxy-4-(prop-2-en-1-yl)phenoxy]propane

2020 ◽  
Vol 76 (3) ◽  
pp. 344-348 ◽  
Author(s):  
Abdelmaoujoud Taia ◽  
Mohamed Essaber ◽  
Tuncer Hökelek ◽  
Abdeljalil Aatif ◽  
Joel T. Mague ◽  
...  
Keyword(s):  
Crystal Structure ◽  
Surface Analysis ◽  
Density Functional ◽  
Energy Gap ◽  
Crystal Packing ◽  
Hirshfeld Surface ◽  
Molecular Structures ◽  
Hirshfeld Surface Analysis ◽  
Functional Theory ◽  
Compound C

The asymmetric unit of the title compound, C23H28O4, comprises two half-molecules, with the other half of each molecule being completed by the application of twofold rotation symmetry. The two completed molecules both have a V-shaped appearance but differ in their conformations. In the crystal, each independent molecule forms chains extending parallel to the b axis with its symmetry-related counterparts through C—H...π(ring) interactions. Hirshfeld surface analysis of the crystal structure indicates that the most important contributions for the crystal packing are from H...H (65.4%), H...C/C...H (21.8%) and H...O/O...H (12.3%) interactions. Optimized structures using density functional theory (DFT) at the B3LYP/6–311 G(d,p) level are compared with the experimentally determined molecular structures in the solid state. The HOMO–LUMO behaviour was elucidated to determine the energy gap.

scholarly journals Crystal structure of the mineral strontiodresserite from laboratory powder diffraction data

2010 ◽  
Vol 25 (4) ◽  
pp. 322-328 ◽  
Author(s):  
P. S. Whitfield ◽  
L. D. Mitchell ◽  
Y. Le Page ◽  
J. Margeson ◽  
A. C. Roberts
Keyword(s):  
Crystal Structure ◽  
Powder Diffraction ◽  
Diffraction Data ◽  
Density Functional ◽  
Powder Diffraction Data ◽  
Hydrogen Atoms ◽  
Functional Theory ◽  
Space Group ◽  
Hydrogen Bond Networks ◽  
The Stability

The crystal structure of the mineral strontiodresserite, (Sr,Ca)Al2(CO3)2(OH)4⋅H2O, from the Francon Quarry, Montreal, Quebec, Canada, has been solved from laboratory powder diffraction data using a combination of charge-flipping and simulated annealing methods. The structure is orthorhombic in space group Pnma with a=16.0990(7), b=5.6133(3), and c=9.1804(4) Å (Z=4) and the framework of the mineral is isostructural with that of dundasite. The strontium has a coordination number of 9 and the carbonate anions form a bridge between the SrO9 polyhedra and AlO6 octahedra. The water molecule lies in a channel that runs parallel to the b axis. An ordered network of hydrogen atoms could be uniquely determined from crystal-chemical principles in the channels of strontiodresserite. Ab initio density functional theory (DFT) energy minimization of the whole structure gave results in full agreement with X-ray refinement results for nonhydrogen atoms. The stability of this model (as well as that of the corresponding model of dundasite) in the proposed Pnma space group was tested by DFT optimization in space group P1 of random small distortions of this structure. This test confirms that both minerals are isostructural, including their hydrogen-bond networks.

scholarly journals The crystal structure of Rb2Ti2O5

2017 ◽  
Vol 73 (6) ◽  
pp. 1142-1150 ◽  
Author(s):  
Rémi Federicci ◽  
Benoit Baptiste ◽  
Fabio Finocchi ◽  
Florin Popa ◽  
Luc Brohan ◽  
...  
Keyword(s):  
Crystal Structure ◽  
Density Functional ◽  
Structural Transition ◽  
Ferroelectric Phase ◽  
Density Functional Theory Calculations ◽  
X Ray Diffraction ◽  
Functional Theory ◽  
X Ray ◽  
Transmission Electron ◽  
The Stability

Recent results have demonstrated an exceptionally high permittivity in the range 200–330 K in crystalline titanium oxide Rb2Ti2O5. In this article, the possibility of a structural transition giving rise to ferroelectricity is carefully inspected. In particular, X-ray diffraction, high-resolution transmission electron microscopy and Raman spectroscopy are performed. The crystal structure is shown to remain invariant and centrosymmetric at all temperatures between 90 K and 450 K. The stability of the C2/m structure is confirmed by density functional theory calculations. These important findings allow the existence of a conventional ferroelectric phase transition to be ruled out as a possible mechanism for the colossal permittivity and polarization observed in this material.

scholarly journals Molecular structure, DFT studies and Hirshfeld analysis of anthracenyl chalcone derivatives

2018 ◽  
Vol 74 (6) ◽  
pp. 780-785 ◽  
Author(s):  
Dian Alwani Zainuri ◽  
Ibrahim Abdul Razak ◽  
Suhana Arshad
Keyword(s):  
Crystal Structure ◽  
Electrostatic Potential ◽  
Density Functional ◽  
Molecular Structures ◽  
Functional Theory ◽  
Chalcone Derivatives ◽  
Hirshfeld Analysis ◽  
Intermolecular Contacts ◽  
Fused Ring System ◽  
Homo Lumo

The molecular and crystal structure of two new chalcone derivatives, (E)-1-(anthracen-9-yl)-3-[4-(piperidin-1-yl)phenyl]prop-2-en-1-one, C28H25NO, (I), and (E)-1-(anthracen-9-yl)-3-[4-(diphenylamino)phenyl]prop-2-en-1-one, C35H25NO, (II), with the fused-ring system at the same position are described. In the crystals of (I) and (II), the molecules are linked via C—H...O hydrogen bonds into inversion dimers, forming R 2 2(22) and R 2 2(14) ring motifs, respectively. Weak intermolecular C—H...π interactions further help to stabilize the crystal structure, forming a two-dimensional architecture. The molecular structures are optimized using density functional theory (DFT) at B3LYP/6–311 G++(d,p) level and compared with the experimental results. The smallest HOMO–LUMO energy gaps of (I) (exp . 2.76 eV and DFT 3.40 eV) and (II) (exp . 2.70 eV and DFT 3.28 eV) indicates the suitability of these crystals in optoelectronic applications. All intermolecular contacts and weaker contributions involved in the supramolecular stabilization are investigated using Hirshfeld surface analysis. The molecular electrostatic potential (MEP) further identifies the positive, negative and neutral electrostatic potential regions of the molecules.

Thermodynamic Stability of Hexagonal and Rhombohedral Bn at Cvd Conditions from Van der Waals Corrected First Principles Calculations

2019 ◽  
Author(s):  
Henrik Pedersen ◽  
Björn Alling ◽  
Hans Högberg ◽  
Annop Ektarawong
Keyword(s):  
Thin Films ◽  
Thermodynamic Stability ◽  
First Principles ◽  
Thermal Equilibrium ◽  
Density Functional ◽  
Van Der Waals ◽  
Chemical Vapor ◽  
First Principles Calculations ◽  
Functional Theory ◽  
The Stability

Thin films of boron nitride (BN), particularly the sp<sup>2</sup>-hybridized polytypes hexagonal BN (h-BN) and rhombohedral BN (r-BN) are interesting for several electronic applications given band gaps in the UV. They are typically deposited close to thermal equilibrium by chemical vapor deposition (CVD) at temperatures and pressures in the regions 1400-1800 K and 1000-10000 Pa, respectively. In this letter, we use van der Waals corrected density functional theory and thermodynamic stability calculations to determine the stability of r-BN and compare it to that of h-BN as well as to cubic BN and wurtzitic BN. We find that r-BN is the stable sp<sup>2</sup>-hybridized phase at CVD conditions, while h-BN is metastable. Thus, our calculations suggest that thin films of h-BN must be deposited far from thermal equilibrium.

Synthesis, Conformational Analysis and Crystal Structure of New Thioxo, Oxo, Seleno Diastereomeric Cyclophosphamides Containing 1,3,2-dioxaphosphorinane

2019 ◽  
Vol 23 (2) ◽  
pp. 205-213
Author(s):  
Dorra Kanzari-Mnallah ◽  
Med L. Efrit ◽  
Jiří Pavlíček ◽  
Frédéric Vellieux ◽  
Habib Boughzala ◽  
...  
Keyword(s):  
Molecular Structure ◽  
Crystal Structure ◽  
Density Functional ◽  
Chemical Shifts ◽  
Structural Determination ◽  
Conformational Study ◽  
Functional Theory ◽  
One Step ◽  
High Resolution Mass Spectroscopy ◽  
Resolution Mass

Thioxo, Oxo and Seleno diastereomeric cyclophosphamides containing 1,3,2- dioxaphosphorinane are prepared by a one-step chemical reaction. Their structural determination is carried out by means of Nuclear Magnetic Resonance NMR (31P, 1 H, 13C) and High-Resolution Mass Spectroscopy (HRMS). The conformational study of diastereomeric products is described. Density Functional Theory (DFT) calculations allowed the identification of preferred conformations. Experimental and calculated 31P, 13C, 1H NMR chemical shifts are compared. The molecular structure of the 2-Benzylamino-5-methyl-5- propyl-2-oxo-1,3,2-dioxaphosphorinane (3d) has been determined by means of crystal Xray diffraction methods.

scholarly journals Exo⇔Endo Isomerism, MEP/DFT, XRD/HSA-Interactions of 2,5-Dimethoxybenzaldehyde: Thermal, 1BNA-Docking, Optical, and TD-DFT Studies

Molecules ◽  
2020 ◽  
Vol 25 (24) ◽  
pp. 5970
Author(s):  
Nabil Al-Zaqri ◽  
Mohammed Suleiman ◽  
Anas Al-Ali ◽  
Khaled Alkanad ◽  
Karthik Kumara ◽  
...  
Keyword(s):  
Density Functional ◽  
Energy Gap ◽  
Structural Parameters ◽  
Population Analysis ◽  
Xrd Analysis ◽  
X Ray Diffraction ◽  
Optical Energy Gap ◽  
Functional Theory ◽  
Reactivity Descriptors ◽  
Td Dft

The exo⇔endo isomerization of 2,5-dimethoxybenzaldehyde was theoretically studied by density functional theory (DFT) to examine its favored conformers via sp2–sp2 single rotation. Both isomers were docked against 1BNA DNA to elucidate their binding ability, and the DFT-computed structural parameters results were matched with the X-ray diffraction (XRD) crystallographic parameters. XRD analysis showed that the exo-isomer was structurally favored and was also considered as the kinetically preferred isomer, while several hydrogen-bonding interactions detected in the crystal lattice by XRD were in good agreement with the Hirshfeld surface analysis calculations. The molecular electrostatic potential, Mulliken and natural population analysis charges, frontier molecular orbitals (HOMO/LUMO), and global reactivity descriptors quantum parameters were also determined at the B3LYP/6-311G(d,p) level of theory. The computed electronic calculations, i.e., TD-SCF/DFT, B3LYP-IR, NMR-DB, and GIAO-NMR, were compared to the experimental UV–Vis., optical energy gap, FTIR, and 1H-NMR, respectively. The thermal behavior of 2,5-dimethoxybenzaldehyde was also evaluated in an open atmosphere by a thermogravimetric–derivative thermogravimetric analysis, indicating its stability up to 95 °C.

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