scholarly journals Crystal structure of tert-butyl 4-[4-(4-fluorophenyl)-2-methylbut-3-yn-2-yl]piperazine-1-carboxylate

2021 ◽  
Vol 77 (4) ◽  
pp. 360-365
Author(s):  
Ashwini Gumireddy ◽  
Kevin DeBoyace ◽  
Alexander Rupprecht ◽  
Mohit Gupta ◽  
Saloni Patel ◽  
...  
Keyword(s):  
Crystal Structure ◽  
Crystal Packing ◽  
Chair Conformation ◽  
The Novel ◽  
Weak Hydrogen Bond ◽  
Dispersion Interactions ◽  
Fingerprint Analysis ◽  
Piperazine Ring ◽  
Structural Database

The title sterically congested piperazine derivative, C20H27FN2O2, was prepared using a modified Bruylants approach. A search of the Cambridge Structural Database identified 51 compounds possessing an N-tert-butyl piperazine substructure. Of these only 14 were asymmetrically substituted on the piperazine ring and none with a synthetically useful second nitrogen. Given the novel chemistry generating a pharmacologically useful core, determination of the crystal structure for this compound was necessary. The piperazine ring is present in a chair conformation with di-equatorial substitution. Of the two N atoms, one is sp 3 hybridized while the other is sp 2 hybridized. Intermolecular interactions resulting from the crystal packing patterns were investigated using Hirshfeld surface analysis and fingerprint analysis. Directional weak hydrogen-bond-like interactions (C—H...O) and C—H...π interactions with the dispersion interactions as the major source of attraction are present in the crystal packing.

Crystal structure determination of the conformation of two bicyclo[3.3.1]nonan-ones

1985 ◽  
Vol 63 (6) ◽  
pp. 1166-1169 ◽  
Author(s):  
John F. Richardson ◽  
Ted S. Sorensen
Keyword(s):  
Crystal Structure ◽  
Direct Methods ◽  
Chair Conformation ◽  
Molecular Structures ◽  
Boat Conformation ◽  
X Ray Diffraction ◽  
Space Group ◽  
X Ray ◽  
Final Agreement

The molecular structures of exo-7-methylbicyclo[3.3.1]nonan-3-one, 3, and the endo-7-methyl isomer, 4, have been determined using X-ray-diffraction techniques. Compound 3 crystallizes in the space group [Formula: see text] with a = 15.115(1), c = 7.677(2) Å, and Z = 8 while 4 crystallizes in the space group P21 with a = 6.446(1), b = 7.831(1), c = 8.414(2) Å, β = 94.42(2)°, and Z = 2. The structures were solved by direct methods and refined to final agreement factors of R = 0.041 and R = 0.034 for 3 and 4 respectively. Compound 3 exists in a chair–chair conformation and there is no significant flattening of the chair rings. However, in 4, the non-ketone ring is forced into a boat conformation. These results are significant in interpreting what conformations may be present in the related sp2-hybridized carbocations.

scholarly journals Crystal structure of 2-(2,4-diphenyl-3-azabicyclo[3.3.1]nonan-9-ylidene)acetonitrile

2015 ◽  
Vol 71 (10) ◽  
pp. o792-o793
Author(s):  
K. Priya ◽  
K. Saravanan ◽  
S. Kabilan ◽  
S. Selvanayagam
Keyword(s):  
Crystal Structure ◽  
Hydrogen Bonding ◽  
Crystal Packing ◽  
Van Der Waals ◽  
Van Der Waals Forces ◽  
Chair Conformation ◽  
Equatorial Orientation ◽  
Amino Group ◽  
Phenyl Rings

In the title 3-azabicyclononane derivative, C22H22N2, both the fused piperidine and cyclohexane rings adopt a chair conformation. The phenyl rings attached to the central azabicylononane fragment in an equatorial orientation are inclined to each other at 23.7 (1)°. The amino group is not involved in any hydrogen bonding, so the crystal packing is stabilized only by van der Waals forces.

scholarly journals Fluphenazine dihydrochloride dimethanol solvate

2012 ◽  
Vol 68 (4) ◽  
pp. o1004-o1005 ◽  
Author(s):  
Joanna Petrus ◽  
Rafał Petrus ◽  
Bogusława Czarnik-Matusewicz
Keyword(s):  
Crystal Structure ◽  
Hydrogen Bonds ◽  
Dihedral Angle ◽  
Title Compound ◽  
Chair Conformation ◽  
Piperazine Ring ◽  
Benzene Rings

In the title compound {systematic name: 1-(2-hydroxyethyl)-4-[3-(2-trifluoromethyl-10H-phenothiazin-10-yl)propyl]piperazine-1,4-diium dichloride dimethanol disolvate}, C22H28F3N3OS2+·2Cl−·2CH3OH, the dihedral angle between the planes of the two outer benzene rings of the tricyclic phenothiazine system is 46.91 (13)°. The piperazine ring adopts a chair conformation. The crystal structure is stabilized by O—H...Cl, N—H...Cl, C—H...O, C—H...Cl and C—H...F hydrogen bonds and contacts.

scholarly journals NMR crystallography, diffraction and modeling of small organic molecules

2014 ◽  
Vol 70 (a1) ◽  
pp. C1088-C1088
Author(s):  
Luís Miguel Monteiro Mafra
Keyword(s):  
Crystal Structure ◽  
Solid State ◽  
Crystal Packing ◽  
Computational Study ◽  
Chemical Shifts ◽  
Hybrid Approach ◽  
X Ray Diffraction ◽  
Structure Solution ◽  
Nmr Crystallography

Solid-state NMR (SSNMR) is a powerful atomic-level characterization technique able to study the local chemical environment of a nucleus in crystalline/amorphous solids. Toward a better understanding of how small molecules self-assemble in the solid-state and reorganizes to produce its hydrate/anhydrous forms, an experimental SSNMR, X-ray diffraction (XRD), and computational study of the supramolecular assemblies of selected small pharmaceuticals is presented. The effect of crystal packing on the 1H and 13C chemical shifts including nonconventional hydrogen bonds, pi···pi and CH···pi contacts, is studied through computer simulations. It will be shown that NMR chemical shifts are sensitive detectors of hydration/dehydration states in highly insoluble antibiotics.[1] Recently, SSNMR became an important gadget in the process of crystal structure solution in powders. This is a non-trivial task and using powder XRD methods alone may often lead to the wrong structure solution. In this talk, a new hybrid approach for structure determination of crystalline solids, will be presented, based on the combination of SSNMR, XRD and an ensemble of computational-assisted structure solution tools including a genetic algorithm based on evolution-inspired operators repeatedly applied to populations of possible crystal structure solutions that evolve to eventually produce the best new offspring candidates. Such methodologies are successfully applied to challenging cases involving multiple component crystals composed by flexible molecules such as a trihydrate β-lactamic antibiotic [2] and an azole-based co-crystal featuring an hydrogen bond network of α-helixes involving NH···N/CH···π intermolecular interactions. ACKNOLEDGEMENTS: Supported by Fundação para a Ciência e a Tecnologia (FCT), Portuguese National NMR Network (RNRMN), CICECO (PEst-C/CTM/LA0011/2013), FEDER, COMPETE, and University of Aveiro. FCT is greatly acknowledge for the consolidation grant IF/01401/2013.

scholarly journals Crystal structure of bis(azido-κN)bis(quinolin-8-amine-κ2N,N′)iron(II)

2016 ◽  
Vol 72 (10) ◽  
pp. 1488-1491
Author(s):  
Fatima Setifi ◽  
Dohyun Moon ◽  
Robeyns Koen ◽  
Zouaoui Setifi ◽  
Morad Lamsayah ◽  
...  
Keyword(s):  
Crystal Structure ◽  
Magnetic Properties ◽  
Structure Determination ◽  
Crystal Packing ◽  
Octahedral Geometry ◽  
Title Complex ◽  
Two Dimensional ◽  
Azide Ion ◽  
Amine Ligands

The search for new molecular materials with interesting magnetic properties using the pseudohalide azide ion and quinolin-8-amine (aqin, C9H8N2) as a chelating ligand, led to the synthesis and structure determination of the title complex, [Fe(N3)2(C9H8N2)2]. The complex shows an octahedral geometry, with the FeIIatom surrounded by six N atoms; the two N3−anions coordinate in acisconfiguration, while the remaining N atoms originate from the two quinolin-8-amine ligands with the quinoline N atoms lying on opposite sides of the Fe atom. The crystal packing is dominated by layers of hydrophilic and aromatic regions parallel to theacplane, stabilized by a two-dimensional hydrogen-bonded network and π–π stacking.

scholarly journals Crystal structure of 2,6-bis(2,5-dimethoxyphenyl)-3,5-dimethylpiperidin-4-one

2014 ◽  
Vol 70 (11) ◽  
pp. o1160-o1160
Author(s):  
Dong Ho Park ◽  
V. Ramkumar ◽  
P. Parthiban
Keyword(s):  
Crystal Structure ◽  
Crystal Packing ◽  
Van Der Waals ◽  
Chair Conformation ◽  
Piperidine Ring ◽  
Benzene Rings ◽  
Title Molecule ◽  
Van Der Waals Contacts

In the title molecule, C23H29NO5, the central piperidine ring has a chair conformation. The planes of the two benzene rings are inclined each to other at 61.7 (1)°. The crystal packing exhibits no directional interactions only van der Waals contacts.

scholarly journals Crystal structure of ethyl 2-phenyl-4-(prop-2-yn-1-yloxy)-5,6,7,8-tetrahydropyrido[4′,3′:4,5]thieno[2,3-d]pyrimidine-7-carboxylate

2015 ◽  
Vol 71 (11) ◽  
pp. o836-o837
Author(s):  
Mehmet Akkurt ◽  
Victoria A. Smolenski ◽  
Shaaban K. Mohamed ◽  
Jerry P. Jasinski ◽  
Essam K Ahmed ◽  
...  
Keyword(s):  
Crystal Structure ◽  
Hydrogen Bonds ◽  
Phenyl Ring ◽  
Crystal Packing ◽  
Three Dimensional ◽  
Chair Conformation ◽  
Pyrimidine Ring ◽  
Ring System ◽  
Compound C ◽  
Dimensional Crystal

In the title compound, C21H19N3O3S, the 5,6,7,8-tetrahydropyridine ring adopts a half-chair conformation. The fused-thieno[2,3-d]pyrimidine ring system is essentially planar (r.m.s. deviation = 0.001 Å) and forms a dihedral angle of 2.66 (6)° with the attached phenyl ring. The three-dimensional crystal packing is stabilized by C—H...O and C—H...N hydrogen bonds and C—H...π interactions.

scholarly journals Synthesis, crystal structure and biological activity of copper(II) complex with 4-nitro-3-pyrazolecarboxylic ligand

2020 ◽  
Vol 85 (7) ◽  
pp. 885-895
Author(s):  
Milica Kosovic ◽  
Sladjana Novakovic ◽  
Zeljko Jacimovic ◽  
Nedeljko Latinovic ◽  
Nada Markovic ◽  
...  
Keyword(s):  
Crystal Structure ◽  
Biological Activity ◽  
Octahedral Coordination ◽  
Biological Research ◽  
Coordination Geometry ◽  
X Ray Diffraction ◽  
X Ray ◽  
Structural Database ◽  
Commercial Fungicide

The reaction of 4-nitro-3-pyrazolecarboxylic acid and Cu(OAc)2?H2O in ethanol resulted in a new coordination compound [Cu2(4-nitro-3- -pzc)2(H2O)6]2H2O (4nitro-3pzc = 4-nitro-3-pyrazolecarboxylate). The compound was investigated by means of single-crystal X-ray diffraction and infrared spectroscopy. The biological activity of the complex was also tested. In the crystal structure of [Cu2(4nitro-3-pzc)2(H2O)6]2H2O, the Cu(II) ion is in a distorted [4+2] octahedral coordination due to the Jan?Teller effect. A survey of the Cambridge Structural Database showed that the octahedral coordination geometry is generally rare for pyrazole-bridged Cu(II) complexes. In the case of Cu(II) complexes with the 3-pyrazolecarboxylato ligands, no complexes with a similar octahedral coordination geometry have been reported. Biological research based on determination of the inhibition effect of the commercial fungicide Cabrio top and the newly synthesized complex on Ph. viticola were performed using the phytosanitary method.

scholarly journals Reactions of copper(II) bromide with 2,6-diacetylpyridine bis(phenyl-hydrazone) (L)-molecular and crystal structure of L and its mixed-valence complex [cuiil2][cui2br4]

2021 ◽  
pp. 112-112
Author(s):  
Marko Rodic ◽  
Mirjana Radanovic ◽  
Dragana Gazdic ◽  
Vukadin Leovac ◽  
Berta Barta-Holló ◽  
...  
Keyword(s):  
Crystal Structure ◽  
Thermal Stability ◽  
Crystal Packing ◽  
Complex Cation ◽  
Mixed Valence ◽  
Molecular Structures ◽  
Planar Geometry ◽  
Dispersion Interactions ◽  
X Ray Crystallography ◽  
Thermal Stability Of

Utilizing X-ray crystallography the crystal and molecular structures of 2,6-diacetylpyridine bis(phenylhydrazone) (L) were determined. Energetics of the intermolecular interactions in the crystal structure was assessed with computational methods, revealing that dispersion interactions are dominant. The basic structural unit of the crystal packing is revealed to be the herring-bone type arrangement of L molecules. Assignation of the IR spectrum of L with the aid of DFT calculations was performed. Furthermore, new reactions of L with CuBr2 in different solvents are described, which led to the synthesis of the mixed Cu(II)-Cu(I) complex of the formula [CuIIL2][CuI2Br4] (1), and its structural characterization. In the complex cation, two molecules of tridentate N3 ligand are meridionally arranged in a very distorted octahedral environment of a Cu(II) ion. In [Cu2Br4]2-, bromide ions are arranged in a trigonal-planar geometry around each copper(I) atom. Finally, for the ligand, 1, and the previously synthesized complex [CuL2]Br2, thermal properties were examined. The thermal stability of the com-plexes is lower than that of the ligand and decreases in order: L (250?C) > > [CuL2]Br2 (221?C) > [CuIIL2][CuI2Br4] (212?C). The differences in thermal stability of the complexes are due to differences in packing efficacy of the constitutional ions.

The Structure of the Novel Lichen Xanthone Thiomelin and Its Cogenors

1987 ◽  
Vol 40 (7) ◽  
pp. 1169 ◽  
Author(s):  
JA Elix ◽  
KL Gaul ◽  
M Sterns ◽  
MW Binsamsudin
Keyword(s):  
Crystal Structure ◽  
Structure Determination ◽  
Ring Opening ◽  
Spectroscopic Data ◽  
The Novel ◽  
X Ray Diffraction ◽  
X Ray ◽  
Lichen Metabolite

The structure determination of thiomelin (2,4-dichloro-1,8-dihydroxy-5-methoxy-6-methyl-9H-xanthen-9-one) (3), an unusual lichen metabolite probably derived biosynthetically by oxidative ring opening of a precursor anthraquinone, is reported. The crystal structure of thiomelin diacetate (4) was determined by X-ray diffraction, while that of the cogenors 8-O-methylthiomelin (5), 4-dechlorothiomelin (7), 4-dechloro-8- O- methylthiomelin (9), 2-dechloro-8- O- methylthiomelin (10) and 2,4-dichloro-l-hydroxy-7-methoxy-6,8-dimethyl-9H-xanthen-9-one (12) were deduced from spectroscopic data.

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