scholarly journals Reversible De-/Rehydration Process in Paroxetine Hydrobromide

2014 ◽  
Vol 70 (a1) ◽  
pp. C999-C999
Author(s):  
Paulo Carvalho-Jr ◽  
Javier Ellena ◽  
Alejandro Ayala
Keyword(s):  
Crystal Structure ◽  
Crystal Packing ◽  
Pharmaceutical Formulations ◽  
Ambient Atmosphere ◽  
X Ray Diffraction ◽  
Scanning Calorimetry ◽  
X Ray ◽  
The Stability ◽  
Dehydration Behavior ◽  
Rehydration Process

Paroxetine (PRX) is an antidepressant widely used in depression treatment for decades. The anhydrous and hemidrate chloride forms have been used in pharmaceutical formulations. During their developing a discussion associated with its physical forms and the complex hydration/dehydration behavior involving these phases were established. To improve our understanding of this issue we investigate the crystal structure of paroxetine bromide hemidrate, (PRX+.Br-).H2O, as a model for understanding the stability anhydrous/hemihydrate paroxetine arrangements and the nature of the intermolecular interaction of water within the crystal lattice by single crystal X-ray diffraction experiments. A combination of complementary characterization techniques were also used including Differential Scanning Calorimetry (DSC), thermogravimetric analysis (TGA), Hot Stage microscopy and solubility measurements. As expected the paroxetine bromide hemidrate, (PRX+.Br-).H2O, is isostructural with the paroxetine chloride hemidrate, (PRX+.Cl-).H2O. As in that case, the crystal packing of (PRX+.Br-).H2O is stabilized by strong NH2+...O and NH2+...Br hydrogen bonds which forms infinite channels along the b axis. The water and bromide anions are located along these channels. The DSC/TGA analysis for (PRX+.Br-).H2O show an endothermic desolvation process with an onset temperature of 77.09 °C, that is not present in the paroxetine chloride hemidrate DSC curve. This process leaves to a paroxetine anhydrous bromide crystal structure that is isomorphic to the anhydrous chloride one. However, this structure is spontaneously rehydrated at ambient atmosphere. This rehydration phenomenon probe the stability of paroxetine hemihydrate arrangement, since (PRX+.Br-) is slightly more soluble that its hydrate form. As opposed to chloride hemidrate, the rehydration of paroxetine bromide only involves a rearrangement of the water molecule within the cavities.

Comparison of the crystal structures and thermochemistry of a novel soluble guanylate cyclase stimulator riociguat and its solvates

2017 ◽  
Vol 73 (5) ◽  
pp. 891-898 ◽  
Author(s):  
Xinbo Zhou ◽  
Xiurong Hu ◽  
Jianming Gu ◽  
Jianrong Zhu
Keyword(s):  
Crystal Structure ◽  
Thermogravimetric Analysis ◽  
Crystal Structures ◽  
Guanylate Cyclase ◽  
Soluble Guanylate Cyclase ◽  
Crystal Packing ◽  
X Ray Diffraction ◽  
Scanning Calorimetry ◽  
X Ray ◽  
Soluble Guanylate Cyclase Stimulator

Riociguat (Rio) is the first oral soluble guanylate cyclase stimulator to be approved for pulmonary arterial hypertension. In this study, form (II) of riociguat and three solvates with acetonitrile [form (III)],N,N-dimethylformamide [form (IV)] and ethyl acetate [form (V)] were crystallized. They were identified and characterized by differential scanning calorimetry, thermogravimetric analysis, X-ray powder diffraction, and their crystal structures were determined by single-crystal X-ray diffraction. No crystal structure has previously been reported for the known form (II) of riociguat. Crystal structure determination of Rio and its new solvates revealed that the dimericR22(14) motif is common in both structures. The crystal packing of solvates adopts channel-like patterns, whereas form (II) of riociguat adopts sheet-like patterns. Strong π–π interactions exist in the above four forms. The conformation of the riociguat in one molecule of 0.5-DMF solvate was found to be significantly different from the conformations found in the other solvates. Desolvation of the three solvates was studied by thermogravimetric analysis and X-ray diffraction, and was shown to transform them into form (I) of riociguat.

Study on a Novel Structure of Zn Phenanthroline Malic Acid Hydrate, [Zn (C12H8N2)(C4H4O5)(H2O)](H2O)

2013 ◽  
Vol 739 ◽  
pp. 26-29
Author(s):  
Hai Xing Liu ◽  
Jing Zhong Xiao ◽  
Huan Mei Guo ◽  
Qing Hua Zhang ◽  
Zhang Xue Yu ◽  
...  
Keyword(s):  
Crystal Structure ◽  
Malic Acid ◽  
Hydrothermal Reaction ◽  
Crystal Packing ◽  
X Ray Diffraction ◽  
Acid Anion ◽  
X Ray ◽  
Hydrogen Bonding Interactions ◽  
Novel Structure ◽  
Acid Hydrate

A novel Zn complex [Zn (C12H8N2)(C4H4O5)(H2O)](H2O) has been synthesized from a hydrothermal reaction and the crystal structure has been determined by means of single-crystal X-ray diffraction. The Zn atom is six-coordinated by two phenanthroline N atoms, three O atoms from malic acid anion and one O atom from water. The crystal packing is stabilized by O-H...O hydrogen bonding interactions.

scholarly journals Synthesis and Complexation Properties of 2-Hydroxy-5-methoxyphenylphosphonic Acid (H3L1). Crystal Structure of the [Cu(H2L1)2(Н2О)2] Complex

2021 ◽  
Vol 91 (11) ◽  
pp. 2176-2186
Author(s):  
G. S. Tsebrikova ◽  
Yu. I. Rogacheva ◽  
I. S. Ivanova ◽  
A. B. Ilyukhin ◽  
V. P. Soloviev ◽  
...  
Keyword(s):  
Crystal Structure ◽  
Hydrogen Bond ◽  
Methoxy Group ◽  
Protonation Constants ◽  
Water Molecules ◽  
X Ray Diffraction ◽  
X Ray ◽  
The Stability ◽  
Intramolecular Hydrogen ◽  
Oxygen Atoms

Abstract 2-Hydroxy-5-methoxyphenylphosphonic acid (H3L1) and the complex [Cu(H2L1)2(H2O)2] were synthesized and characterized by IR spectroscopy, thermogravimetry, and X-ray diffraction analysis. The polyhedron of the copper atom is an axially elongated square bipyramid with oxygen atoms of phenolic and of monodeprotonated phosphonic groups at the base and oxygen atoms of water molecules at the vertices. The protonation constants of the H3L1 acid and the stability constants of its Cu2+ complexes in water were determined by potentiometric titration. The protonation constants of the acid in water are significantly influenced by the intramolecular hydrogen bond and the methoxy group. The H3L1 acid forms complexes CuL‒ and CuL24‒ with Cu2+ in water.

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.

Study of thermal properties of Ga0.5In1.5Se3 by differential scanning calorimetry

2021 ◽  
pp. 2150407
Author(s):  
S. I. Ibrahimova
Keyword(s):  
Crystal Structure ◽  
Differential Scanning Calorimetry ◽  
Thermal Properties ◽  
Thermal Effects ◽  
Room Temperature ◽  
Structural Studies ◽  
X Ray Diffraction ◽  
Hexagonal Symmetry ◽  
Scanning Calorimetry ◽  
X Ray

The crystal structure and thermal properties of the [Formula: see text] compound have been investigated. Structural studies were performed by X-ray diffraction at room temperature. The crystal structure of this compound was found to correspond to the hexagonal symmetry of the space group P61. Thermal properties were studied using a differential scanning calorimetry (DSC). It was found in the temperature range [Formula: see text] that thermal effects occur at temperatures [Formula: see text] and [Formula: see text]. The thermodynamic parameters of these effects are calculated.

The new barium compound Ba4Al7+x: formation and crystal structure

2016 ◽  
Vol 71 (5) ◽  
pp. 611-619 ◽  
Author(s):  
Yurii Prots ◽  
Felix Lange ◽  
Christina Drathen ◽  
Marcus Schmidt ◽  
Yuri Grin
Keyword(s):  
Crystal Structure ◽  
Structural Model ◽  
Model Space ◽  
Binary Compound ◽  
Formation Temperature ◽  
X Ray Diffraction ◽  
Scanning Calorimetry ◽  
Laves Phases ◽  
X Ray

AbstractCombining laboratory X-ray powder diffraction with in-situ high-temperature synchrotron experiments and differential scanning calorimetry, it has been shown that Ba21Al40, Ba3Al5, Ba7Al10 and Ba4Al5 decompose peritectically at 914, 826, 756, and 732°C, respectively. In addition, a new binary compound with the composition Ba4Al7+x (x = 0.17) and the formation temperature of 841°C was found. The initial structural model (space group P63/mmc, a = 6.0807(1), c = 39.2828(8) Å) with four Ba and five Al crystallographic positions was developed. It is based on the intergrowth concept involving the neighboring Ba21Al40 and Ba3Al5 phases and the derived atomic arrangement is subsequently refined using X-ray diffraction data. The crystal structures of all phases in the Ba–Al system, except BaAl4, exhibit Kagomé nets of aluminum atoms resembling those observed for the B atoms in the Laves phases AB2. In the crystal structure of Ba4Al7+x, single Kagomé layers alternate with double slabs (MgZn2 motif) along [001] and are separated by Ba cations. Intergrowth features of Ba4Al7+x are discussed together with the neighboring Ba–Al compounds and Sr5Al9.

scholarly journals Synthesis and Crystal Structure of the Bioinorganic Complex [Sb(Hedta)]·2H2O

2014 ◽  
Vol 2014 ◽  
pp. 1-7 ◽  
Author(s):  
Di Li ◽  
Guo-Qing Zhong
Keyword(s):  
Crystal Structure ◽  
Ethylenediaminetetraacetic Acid ◽  
Raw Materials ◽  
X Ray Diffraction ◽  
Scanning Calorimetry ◽  
X Ray ◽  
Cell Parameters ◽  
Composition And Structure ◽  
Decomposition Processes ◽  
Distorted Trigonal Bipyramid

The antimony(III) complex [Sb(Hedta)]·2H2O was synthesized with ethylenediaminetetraacetic acid (H4edta) and antimonous oxide as main raw materials in aqueous solution. The composition and structure of the complex were characterized by elemental analysis, infrared spectra, single crystal X-ray diffraction, X-ray powder diffraction, thermogravimetry, and differential scanning calorimetry. The crystal structure of the antimony(III) complex belongs to orthorhombic system, space group Pna2(1), with cell parameters ofa=18.4823(18) Å,b=10.9408(12) Å,c=7.3671(5) Å,V=1489.7(2) Å3,Z=4, andDc=1.993 g cm−3. The Sb(III) ion is five-coordinated by two amido N atoms and three carboxyl O atoms from a single Hedta3−ligand, forming a distorted trigonal bipyramid geometry. The thermal decomposition processes of the complex include dehydration, oxidation, and pyrolysis of the ligand, and the last residue is Sb2O3at the temperature of 570°C.

scholarly journals Synthesis and Crystal Structure of C1-Symmetric 3,3′-Bi(1,1′-dinaphthyl-camphopyrazole)

2016 ◽  
Vol 2016 ◽  
pp. 1-5
Author(s):  
Jannis Barrera ◽  
Victoria A. Smolenski ◽  
Jerry P. Jasinski ◽  
Jesús Pastrán
Keyword(s):  
Crystal Structure ◽  
Crystal Packing ◽  
Pyrazole Ring ◽  
Stacking Interactions ◽  
Naphthalene Ring ◽  
X Ray Diffraction ◽  
Synthesis And Crystal Structure ◽  
X Ray ◽  
Group Form ◽  
C Nmr

The compound 3,3′-bi(1,1′-dinaphthyl-camphopyrazole) 1, C42H42O4, was obtained in good yield and structurally characterized by 1H and 13C NMR spectroscopy, elemental analysis, and X-ray diffraction. It consists of a 3,3′-bipyrazole group with each pyrazole ring containing a fused camphor group and a naphthalene ring bonded to the adjacent nitrogen atom in the ring. Both of the trimethyl, 5-membered rings of the fused camphor group form an envelope with the apex carbon atom as the flap in each case. In the crystal, weak π–π stacking interactions are observed between nearby 6-carbon rings of the two naphthalene rings linking the molecules into extended chains. Weak π–ring intermolecular interactions are also observed between naphthalene atoms and pyrazole rings from each of the groups helping to stabilize the crystal packing. No classical hydrogen interactions are formed.

scholarly journals Crystal structure of the DNA sequence d(CGTGAATTCACG)2with DAPI

2017 ◽  
Vol 73 (9) ◽  
pp. 500-504 ◽  
Author(s):  
Hristina I. Sbirkova-Dimitrova ◽  
Boris Shivachev
Keyword(s):  
Crystal Structure ◽  
Crystal Packing ◽  
Minor Groove ◽  
Van Der Waals Interactions ◽  
Water Molecules ◽  
X Ray Diffraction ◽  
Base Pairs ◽  
X Ray ◽  
Dna Molecule ◽  
Dna Fragment

The structure of 4′,6-diamidine-2-phenylindole (DAPI) bound to the synthetic B-DNA oligonucleotide d(CGTGAATTCACG) has been solved in space groupP212121by single-crystal X-ray diffraction at a resolution of 2.2 Å. The structure is nearly isomorphous to that of the previously reported crystal structure of the oligonucleotide d(CGTGAATTCACG) alone. The adjustments in crystal packing between the native DNA molecule and the DNA–DAPI complex are described. DAPI lies in the narrow minor groove near the centre of the B-DNA fragment, positioned over the A–T base pairs. It is bound to the DNA by hydrogen-bonding and van der Waals interactions. Comparison of the two structures (with and without ligand) shows that DAPI inserts into the minor groove, displacing the ordered spine waters. Indeed, as DAPI is hydrophobic it confers this behaviour on the DNA and thus restricts the presence of water molecules.

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.

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