scholarly journals (R)-Baclofen [(R)-4-amino-3-(4-chlorophenyl)butanoic acid]

Author(s):  
Feodor Belov ◽  
Alexander Villinger ◽  
Jan von Langermann

This article provides the first single-crystal XRD-based structure of enantiopure (R)-baclofen (form C), C10H12ClNO2, without any co-crystallized substances. In the enantiopure title compound, the molecules arrange themselves in an orthorhombic crystal structure (space group P212121). In the crystal, strong hydrogen bonds and C—H ... Cl bonds interconnect the zwitterionic molecules.

Crystals ◽  
2021 ◽  
Vol 11 (2) ◽  
pp. 172
Author(s):  
Kirill Shubin ◽  
Agris Bērziņš ◽  
Sergey Belyakov

New pseudopolymorphs of ivermectin (IVM), a potential anti-COVID-19 drug, were prepared. The crystal structure for three pseudopolymorphic crystalline forms of IVM has been determined using single-crystal X-ray crystallographic analysis. The molecular conformation of IVM in crystals has been compared with the conformation of isolated molecules modeled by DFT calculations. In a solvent with relatively small molecules (ethanol), IVM forms monoclinic crystal structure (space group I2), which contains two types of voids. When crystallized from solvents with larger molecules, like γ-valerolactone (GVL) and methyl tert-butyl ether (MTBE), IVM forms orthorhombic crystal structure (space group P212121). Calculations of the lattice energy indicate that interactions between IVM and solvents play a minor role; the main contribution to energy is made by the interactions between the molecules of IVM itself, which form a framework in the crystal structure. Interactions between IVM and molecules of solvents were evaluated using Hirshfeld surface analysis. Thermal analysis of the new pseudopolymorphs of IVM was performed by differential scanning calorimetry and thermogravimetric analysis.


2006 ◽  
Vol 61 (8) ◽  
pp. 979-982 ◽  
Author(s):  
Murat Taş ◽  
Hanife Saraçoğlu ◽  
Hümeyra Bati ◽  
Nezihe Çalışkan ◽  
Orhan Büyükgüngör

The molecules of the title compound, [Cu(C11H13N2O2)2], lie across centres of inversion in space group P21/c and are linked by intermolecular N-H···O and C-H···O hydrogen bonds. The central Cu atom has a slightly distorted square-planar coordination comprised of four N atoms. Cu-N bond distances are 1.975(2) and 2.020(2) Å . The interplanar angle between the phenyl and succinimidato ring is 87.34(10)°


Author(s):  
Jamila Benabdallah ◽  
Zouaoui Setifi ◽  
Fatima Setifi ◽  
Habib Boughzala ◽  
Abderrahim Titi

In the title compound, [Co(C10H8N2)3](C9H5N4O)2, the tris(2,2′-bipyridine)cobalt(II) dication lies across a twofold rotation axes in the space group C2/c. The N atoms of the three bipyridine ligands form a distorted octahedron around the cobalt ion. All the N atoms of the polynitrile 1,1,3,3-tetracyano-2-ethoxypropenide anions participate in C—H...N hydrogen bonds ensuring crystal cohesion and forming a three-dimensional structure. The structure is further stabilized by C—H...π(cation) and anion...π(cation) interactions.


1975 ◽  
Vol 53 (15) ◽  
pp. 2345-2350 ◽  
Author(s):  
Monique Authier-Martin ◽  
André L. Beauchamp

The title compound belongs to space group P21/c with a = 23.99(1), b = 4.245(2), c = 25.98(1) Å, β = 117.58(7)°, and Z = 8. The structure was solved by the heavy-atom method and refined by block-diagonal least squares on 2589 independent observed reflections. All non-hydrogen atoms were refined anisotropically and some of the hydrogen atoms were located but their parameters were not refined. The final values of R and Rw were 0.042 and 0.047, respectively.The two nonequivalent mercury atoms have very similar environments. Two short Hg—Cl bonds (2.34–2.38 Å) at ∼ 165° define a quasi-molecular HgCl2 unit. Overall octahedral coordination is completed with two chloride ions at 2.76–2.84 Å and two chlorine atoms at 3.19–3.26 Å on neighboring HgCl2 quasi-molecules. HgCl6 octahedra share edges to form twofold ribbons in the b direction. This pattern of octahedra is identical with the onereported for β-NH4HgCl3. The cations are pairs of N(1)-protonated adenine molecules linked by two N(10)—H(10)… N(7) hydrogen bonds and stacked in the b direction. Water molecules act as acceptors in moderately strong hydrogen bonds with acidic protons H(1) and H(9) of adeninium ions. Other generally weaker hydrogen bonds exist between the various parts of the structure.


1993 ◽  
Vol 48 (7) ◽  
pp. 961-964 ◽  
Author(s):  
Otto Kumberger ◽  
Jürgen Riede ◽  
Hubert Schmidbaur

A discrete zinc bis[orotate(1—)] complex of the composition Zn(OrH)2·8 H2O has been isolated and characterized by a single-crystal X-ray structure analysis. The crystals are monoclinic, space group P21/c (No. 14), Z = 2, a = 10.884(2), b = 12.896(1), c = 6.954(1) Å, β = 98.27(1)°. The crystal lattice features hexaquo complexes of zinc, the Zn(H2O)62+ cations being associated with two hydrated OrH- ions only through hydrogen bonds. The results are relevant for applications of zinc orotates in medical treatment.


2006 ◽  
Vol 61 (6) ◽  
pp. 727-732 ◽  
Author(s):  
Volodymyr Babizhetskyy ◽  
Constantin Hoch ◽  
Hansjürgen Mattausch ◽  
Arndt Simon

The title compound was prepared from the elements by arc-melting followed by annealing in silica tubes at 1270 K for one week. The crystal structure was investigated by means of X-ray single crystal diffraction: space group P4/mbm, a = 5.366(1), c = 3.690(1) Å , Z = 2, R1 = 0.010, wR2 = 0.022 for 245 unique reflections with Io > 2σ (Io) and 12 refined parameters. Group-subgroup relationships of MB6 and MB2C2 structure models are discussed


Author(s):  
Ioana Sovago ◽  
Matthias J. Gutmann ◽  
Hans Martin Senn ◽  
Lynne H. Thomas ◽  
Chick C. Wilson ◽  
...  

Analysis of neutron and high-resolution X-ray diffraction data on form (III) of carbamazepine at 100 K using the atoms in molecules (AIM) topological approach afforded excellent agreement between the experimental results and theoretical densities from the optimized gas-phase structure and from multipole modelling of static theoretical structure factors. The charge density analysis provides experimental confirmation of the partially localized π-bonding suggested by the conventional structural formula, but the evidence for any significant C—N π bonding is not strong. Hirshfeld atom refinement (HAR) gives H atom positional and anisotropic displacement parameters that agree very well with the neutron parameters. X-ray and neutron diffraction data on the dihydrate of carbemazepine strongly indicate a disordered orthorhombic crystal structure in the space groupCmca, rather than a monoclinic crystal structure in space groupP21/c. This disorder in the dihydrate structure has implications for both experimental and theoretical studies of polymorphism.


1994 ◽  
Vol 59 (6) ◽  
pp. 1361-1367 ◽  
Author(s):  
Alexandr Jegorov ◽  
Roman Sobotík ◽  
Svetlana Pakhomova ◽  
Jan Ondráček ◽  
Jiří Novotný ◽  
...  

The structure of butorphanol hydrogen tartrate {(9R,13S,14S)-(-)-17-(cyclobutylmethyl)morphinan-3,14-diol (2S,3S)-(-)-hydrogen tartrate} (C21H29NO2 .C4H6O6) was solved by direct methods and refined anisotropically to the R value of 0.029 for 2 069 observed reflections. The title morphine analogue crystallizes in the triclinic space group P1 with lattice parameters a = 7.620(1), b = 9.140(1), c = 9.591(1) Å, α = 105.48(1), β = 112.91(1), γ = 84.29(1)°, Z = 1. The butorphanol B ring possesses the 3E envelope conformation with small 3H2 distortion, C and D rings have a regular chair conformation. The intramolecular N17-H17...O2 hydrogen bond is observed in crystal structure of the title compound. The butorphanol and hydrogen tartrate molecules are joined together by means of O2-H(O2)...O7, O1-H(O1)...O7' and O3-H(O3)...O8" hydrogen bonds to form networks.


2013 ◽  
Vol 2013 ◽  
pp. 1-5 ◽  
Author(s):  
Mohamed I. Attia ◽  
Hazem A. Ghabbour ◽  
Aida A. El-Azzouny ◽  
Omar A. Al-Deeb ◽  
Maha S. Almutairi ◽  
...  

Synthesis, spectroscopic characterization and X-ray crystal structure of a new (2E)-2-[3-(1H-imidazol-1-yl)-1-phenylpropylidene]-N-phenylhydrazinecarboxamide (4) are reported. The stereochemistry of the title compound4, C19H19N5O, about the imine bond [1.296 (4) Å] was assigned to have (E)-configuration. In the urea moiety, the N–H entities aretransto each other, and one of these forms is an intramolecular N–H⋯H hydrogen bond. The compound crystallizes in the monoclinic space groupP21/cwitha= 5.8093 (2) Å,b= 20.5575 (6) Å,c= 14.0355 (5) Å,α= 90.00°,β= 97.365° (2),γ= 90.00°,V= 1662.36 (10) Å3, andZ= 4. The molecules are packed in crystal structure by weak intermolecular hydrogen interactions.


Author(s):  
Li Chen ◽  
Xinhua Ma ◽  
ShiHao Deng ◽  
XinZhou Yang ◽  
Ping Song

The title compound, 6,7-dehydroroyleanone, C20H26O3[systematic name: (4bS)-3-hydroxy-2-isopropyl-4b,8,8-trimethyl-4b,5,6,7,8,8a-hexahydrophenanthrene-1,4-dione] was isolated fromTaxodium distichum(L.) Rich. The compound crystallizes in the space groupP21. The crystal structure features two O—H...O hydrogen bonds, forming chains along the [010] direction.


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