scholarly journals Supramolecular construction of a cyclobutane ring system with four different substituents in the solid state

2021 ◽  
Vol 4 (1) ◽  
Author(s):  
Michael A. Sinnwell ◽  
Ryan H. Groeneman ◽  
Benjamin J. Ingenthron ◽  
Changan Li ◽  
Leonard R. MacGillivray
Keyword(s):  
Crystal Engineering ◽  
Materials Science ◽  
Stacking Interactions ◽  
Aromatic Rings ◽  
Structural Units ◽  
Face To Face ◽  
Chiral Carbon ◽  
Biological Compounds ◽  
Carbocyclic Rings ◽  
Cyclobutane Ring

AbstractMethods to form cyclobutane rings by an intermolecular [2 + 2] cross-photoreaction (CPR) with four different substituents are rare. These reactions are typically performed in the liquid phase, involve multiple steps, and generate product mixtures. Here, we report a CPR that generates a cyclobutane ring with four different aryl substituents. The CPR occurs quantitatively, without side products, and without a need for product purification. Generally, we demonstrate how face-to-face stacking interactions of aromatic rings can be exploited in the process of cocrystallization and the field of crystal engineering to stack and align unsymmetrical alkenes in CPRs to afford chiral cyclobutanes with up to four different aryl groups via binary cocrystals. Overall, we expect the process herein to be useful to generate chiral carbon scaffolds, which is important given the presence of four-membered carbocyclic rings as structural units in biological compounds and materials science.

scholarly journals Crystal structure and Hirshfeld surface analysis of (E)-4-{[2,2-dichloro-1-(4-methoxyphenyl)ethenyl]diazenyl}benzonitrile

2019 ◽  
Vol 75 (8) ◽  
pp. 1190-1194
Author(s):  
Mehmet Akkurt ◽  
Namiq Q. Shikhaliyev ◽  
Ulviyya F. Askerova ◽  
Sevinc H. Mukhtarova ◽  
Gunay Z. Mammadova ◽  
...  
Keyword(s):  
Crystal Structure ◽  
Benzene Ring ◽  
Surface Analysis ◽  
Crystal Packing ◽  
Hirshfeld Surface ◽  
Hirshfeld Surface Analysis ◽  
Stacking Interactions ◽  
Aromatic Rings ◽  
Face To Face ◽  
Compound C

In the title compound, C16H11Cl2N3O, the 4-methoxy-substituted benzene ring makes a dihedral angle of 41.86 (9)° with the benzene ring of the benzonitrile group. In the crystal, molecules are linked into layers parallel to (020) by C—H...O contacts and face-to-face π–π stacking interactions [centroid–centroid distances = 3.9116 (14) and 3.9118 (14) Å] between symmetry-related aromatic rings along the a-axis direction. A Hirshfeld surface analysis indicates that the most important contributions to the crystal packing are from Cl...H/H...Cl (22.8%), H...H (21.4%), N...H/H...N (16.1%), C...H/H...C (14.7%) and C...C (9.1%) interactions.

scholarly journals 3-Acetyl-2-fluoro-6H-benzo[c]chromen-6-one

2014 ◽  
Vol 70 (4) ◽  
pp. o470-o471
Author(s):  
Yoshinobu Ishikawa ◽  
Takafumi Suzuki ◽  
Nanako Yoshida
Keyword(s):  
Phenylboronic Acid ◽  
Cross Coupling ◽  
Stacking Interactions ◽  
Asymmetric Unit ◽  
Aromatic Rings ◽  
One Pot ◽  
Face To Face ◽  
Compound C ◽  
Centroid Distance ◽  
Independent Molecules

The title compound, C15H9FO3, was obtained in a one-pot synthesis by Suzuki–Miyaura cross-coupling and nucleophilic substitution reaction of 4′-chloro-2′,5′-difluoroacetophenone witho-(methoxycarbonyl)phenylboronic acid. The asymmetric unit contains two crystallographically independent molecules related by a non-crystallographic inversion centre. There are face-to-face stacking interactions between the aromatic rings of the benzoate and acetophenone units of the symmetry-independent molecules [centroid–centroid distances = 3.870 (3) and 3.986 (3) Å]. In the crystal, molecules are further assembledviastacking interactions along thea-axis direction. One of the molecules interacts with its inversion equivalent [centroid–centroid distance between the aromatic rings of the benzoate and acetophenone units = 3.932 (3) Å], and the other interacts with its twofold axis equivalent [centroid–centroid distance between the aromatic rings of acetophenone units = 3.634 (3) Å].

A Chemical Perspective to the Anti-Amyloid Action of Compounds and a Nanoparticle Based Assay for Screening Amyloid Inhibitors

2020 ◽  
Author(s):  
Nidhi Gour ◽  
Bharti Koshti
Keyword(s):  
Memory Loss ◽  
Cost Effective ◽  
Structural Motif ◽  
Rapid Screening ◽  
Stacking Interactions ◽  
Aromatic Rings ◽  
Amyloid Fibers ◽  
Aromatic Stacking ◽  
Cost Effective Technique ◽  
The Brain

Aggregation of amyloid beeta 1-42 (Aβ<sub>42</sub>) peptide causes the formation of clustered deposits knows as amyloid plaques in the brain which leads to neuronal dysfunction and memory loss and associated with many neurological disorders including Alzheimer’s and Parkinson’s. Aβ<sub>42</sub> has core structural motif with phenylalanine at the 19 and 20 positions. The diphenylalanine (FF) residue plays a crucial role in the formation of amyloid fibers and serves as model peptide for studying Aβ<sub>42 </sub>aggregation. FF self-assembles to well-ordered tubular morphology via aromatic pi-pi stackings. Our studies, suggest that the aromatic rings present in the anti-amyloidogenic compounds may interact with the pi-pi stacking interactions present in the FF. Even the compounds which do not have aromatic rings, like cyclodextrin and cucurbituril show anti-amyloid property due to the binding of aromatic ring inside the guest cavity. Hence, our studies also suggest that compounds which may have a functional moiety capable of interacting with the aromatic stacking interactions might be tested for their anti-amyloidogenic properties. Further, in this manuscript, we have proposed two novel nanoparticle based assays for the rapid screening of amyloid inhibitors. In the first assay, interaction between biotin-tagged FF peptide and the streptavidin labelled gold nanoparticles (s-AuNPs) were used. In another assay, thiol-Au interactions were used to develop an assay for detection of amyloid inhibitors. It is envisaged that the proposed analytical method will provide a simple, facile and cost effective technique for the screening of amyloid inhibitors and may be of immense practical implications to find the therapeutic remedies for the diseases associated with the protein aggregation.

scholarly journals The Face-to-Face σ-Hole···σ-Hole Stacking Interactions: Structures, Energies, and Nature

Crystals ◽  
2021 ◽  
Vol 11 (8) ◽  
pp. 877
Author(s):  
Yu Zhang ◽  
Weizhou Wang
Keyword(s):  
Quantum Chemical ◽  
Noncovalent Interactions ◽  
Electrostatic Energy ◽  
Stacking Interactions ◽  
Energy Component ◽  
Stacking Interaction ◽  
Face To Face ◽  
The Face ◽  
Π Stacking Interaction ◽  
Induction Energy

The existence of the π···π stacking interaction is well-known. Similarly, it is reasonable to assume the existence of the σ-hole···σ-hole stacking interaction. In this work, the structures, energies, and nature of the face-to-face σ-hole···σ-hole stacking interactions in the crystal structures have been investigated in detail by the quantum chemical calculations. The calculated results clearly show that the face-to-face σ-hole···σ-hole stacking interactions exist and have unique properties, although their strengths are not very significant. The energy component analysis reveals that, unlike many other dispersion-dominated noncovalent interactions in which the induction energies always play minor roles for their stabilities, for the face-to-face σ-hole···σ-hole stacking interaction the contribution of the induction energy to the total attractive energy is close to or even larger than that of the electrostatic energy. The structures, energies, and nature of the face-to-face σ-hole···σ-hole stacking interactions confined in small spaces have also been theoretically simulated. One of the important findings is that encapsulation of the complex bound by the face-to-face σ-hole···σ-hole stacking interaction can tune the electronic properties of the container.

scholarly journals (1-Adamantyl){4-[(2-chloro-9-isopropyl-9H-purin-6-yl)aminomethyl]phenyl}methanone trichloromethane solvate

2009 ◽  
Vol 65 (6) ◽  
pp. o1268-o1268 ◽  
Author(s):  
Michal Rouchal ◽  
Marek Nečas ◽  
Robert Vícha
Keyword(s):  
Interplanar Distance ◽  
Maximum Deviation ◽  
Stacking Interactions ◽  
Ring Systems ◽  
Face To Face ◽  
Compound C ◽  
Centroid Distance ◽  
Benzene Rings ◽  
Purine Ring ◽  
Centrosymmetric Dimers

In the title compound, C26H30ClN5O·CHCl3, the purine molecule consists of essentially planar benzene and purine ring systems [maximum deviation 0.010 (4) Å for both ring systems] forming a dihedral angle of 85.52 (9)°. Intermolecular N—H...N hydrogen bonds link adjacent molecules into centrosymmetric dimers. The structure also contains intermolecular C—H...O and C—H...N interactions. The benzene rings form offset face-to-face π–π stacking interactions with an interplanar distance of 3.541 (4) Å and a centroid-to-centroid distance of 4.022 (4) Å.

Microwave-assisted solvent-free synthesis and spectral and structural characterization of cyclotriphosphazene hexakis(o-tolylamide)

2018 ◽  
Vol 73 (12) ◽  
pp. 999-1003 ◽  
Author(s):  
Mohammad Hakimi ◽  
Homeyra Rezaei ◽  
Keyvan Moeini ◽  
Heidar Raissi ◽  
Vaclav Eigner ◽  
...  
Keyword(s):  
Nmr Spectroscopy ◽  
Microwave Irradiation ◽  
Stacking Interactions ◽  
X Ray Diffraction ◽  
Aromatic Rings ◽  
X Ray ◽  
Microwave Assisted ◽  
Ft Ir ◽  
Solvent Free Synthesis

AbstractA new cyclotriphosphazene, 2,2,4,4,6,6-hexakis (o-tolylamono)-1,3,5,2λ5,4λ5,6λ5-triazatriphosphinine (MPAP), was prepared using microwave irradiation and identified by elemental analysis, FT-IR, Raman, 31P NMR spectroscopy, and single-crystal X-ray diffraction. In the crystal, in addition to hydrogen bonds, the network is further stabilized by inter- and intramolecular π–π stacking interactions between aromatic rings.

Crystal Engineering:  Stacking Interactions Control the Crystal Structures of Benzothiadiazole (btd) and Its Complexes with Copper(II) and Copper(I) Chlorides

2001 ◽  
Vol 1 (3) ◽  
pp. 191-194 ◽  
Author(s):  
Giannis S. Papaefstathiou ◽  
Alexandros Tsohos ◽  
Catherine P. Raptopoulou ◽  
Aris Terzis ◽  
Vassilis Psycharis ◽  
...  
Keyword(s):  
Crystal Structures ◽  
Crystal Engineering ◽  
Stacking Interactions

Stacking interactions of resonance-assisted hydrogen-bridged rings and C6-aromatic rings

2020 ◽  
Vol 22 (24) ◽  
pp. 13721-13728 ◽  
Author(s):  
Jelena P. Blagojević Filipović ◽  
Michael B. Hall ◽  
Snežana D. Zarić
Keyword(s):  
Crystal Structures ◽  
Quantum Chemical Calculations ◽  
Quantum Chemical ◽  
Cambridge Structural Database ◽  
Stacking Interactions ◽  
Aromatic Rings ◽  
Structural Database

Stacking interactions between six-membered resonance-assisted hydrogen-bridged (RAHB) rings and C6-aromatic rings have been studied by analyzing crystal structures in the Cambridge Structural Database and performing quantum chemical calculations.

5-Nitrosalicylaldehyde (2-hydroxybenzoyl)hydrazone

2006 ◽  
Vol 62 (7) ◽  
pp. o3026-o3027 ◽  
Author(s):  
Hong-Mei Xu ◽  
Shi-Xiong Liu
Keyword(s):  
Hydrogen Bonds ◽  
Title Compound ◽  
Crystal Packing ◽  
Dihedral Angles ◽  
Stacking Interactions ◽  
Aromatic Rings ◽  
Compound C ◽  
Π Stacking

The molecule of the title compound, C14H11N3O5, is approximately planar, the dihedral angles between the two aromatic rings being 4.63 (7)°. O—H...N, N—H...O and O—H...O hydrogen bonds and π–π stacking interactions help to consolidate the crystal packing.

Reaction-path calculations and crystal structures of 1,1′-(ethylene-1,2-diyl)dipyridinium dichloride dihydrate and 1,1′-(ethylene-1,2-diyl)dipyridinium dibromide

2016 ◽  
Vol 72 (2) ◽  
pp. 112-118
Author(s):  
Mwaffak Rukiah ◽  
Mahmoud M. Al-Ktaifani ◽  
Mohammad K. Sabra
Keyword(s):  
Hydrogen Bonds ◽  
Crystal Engineering ◽  
Materials Science ◽  
Three Dimensional ◽  
X Ray Diffraction ◽  
Substitution Reactions ◽  
Nucleophilic Substitutions ◽  
Triclinic Space Group ◽  
Pyridinium Bromide ◽  
Multinuclear Nmr Spectroscopy

The design of new organic–inorganic hybrid ionic materials is of interest for various applications, particularly in the areas of crystal engineering, supramolecular chemistry and materials science. The monohalogenated intermediates 1-(2-chloroethyl)pyridinium chloride, C5H5NCH2CH2Cl+·Cl−, (I′), and 1-(2-bromoethyl)pyridinium bromide, C5H5NCH2CH2Br+·Br−, (II′), and the ionic disubstituted products 1,1′-(ethylene-1,2-diyl)dipyridinium dichloride dihydrate, C12H14N22+·2Cl−·2H2O, (I), and 1,1′-(ethylene-1,2-diyl)dipyridinium dibromide, C12H14N22+·2Br−, (II), have been isolated as powders from the reactions of pyridine with the appropriate 1,2-dihaloethanes. The monohalogenated intermediates (I′) and (II′) were characterized by multinuclear NMR spectroscopy, while (I) and (II) were structurally characterized using powder X-ray diffraction. Both (I) and (II) crystallize with half the empirical formula in the asymmetric unit in the triclinic space groupP\overline{1}. The organic 1,1′-(ethylene-1,2-diyl)dipyridinium dications, which display approximateC2hsymmetry in both structures, are situated on inversion centres. The components in (I) are linkedviaintermolecular O—H...Cl, C—H...Cl and C—H...O hydrogen bonds into a three-dimensional framework, while for (II), they are connectedviaweak intermolecular C—H...Br hydrogen bonds into one-dimensional chains in the [110] direction. The nucleophilic substitution reactions of 1,2-dichloroethane and 1,2-dibromoethane with pyridine have been investigated byab initioquantum chemical calculations using the 6–31G** basis. In both cases, the reactions occur in two exothermic stages involving consecutive SN2 nucleophilic substitutions. The isolation of the monosubstituted intermediate in each case is strong evidence that the second step is not fast relative to the first.

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