scholarly journals Crystal structure and Hirshfeld analysis of 3′-bromo-4-methylchalcone and 3′-cyano-4-methylchalcone

2020 ◽  
Vol 76 (9) ◽  
pp. 1496-1502
Author(s):  
Zachary O. Battaglia ◽  
Jordan T. Kersten ◽  
Elise M. Nicol ◽  
Paloma Whitworth ◽  
Kraig A. Wheeler ◽  
...  
Keyword(s):  
Crystal Structure ◽  
Hydrogen Atom ◽  
Nitrogen Atom ◽  
Crystal Structures ◽  
Halogen Bond ◽  
Type I ◽  
Large Dataset ◽  
Methyl Substitution ◽  
Hirshfeld Analysis ◽  
Close Contacts

Two crystal structures of chalcones, or 1,3-diarylprop-2-en-1-ones, are presented; both contain a methyl substitution on the 3-Ring, but differ on the 1-Ring, bromo versus cyano. The compounds are 3′-bromo-4-methylchalcone [systematic name: 1-(2-bromophenyl)-3-(4-methylphenyl)prop-2-en-1-one], C16H13BrO, and 3′-cyano-4-methylchalcone {systematic name: 2-[3-(4-methylphenyl)prop-2-enoyl]benzonitrile}, C17H13NO. Both chalcones meaningfully add to the large dataset of chalcone structures. The crystal structure of 3′-cyano-4-methylchalcone exhibits close contacts with the cyano nitrogen that do not appear in previously reported disubstituted cyanochalcones, namely interactions between the cyano nitrogen atom and a ring hydrogen atom as well as a methyl hydrogen atom. The structure of 3′-bromo-4-methylchalcone exhibits a type I halogen bond, similar to that found in a previously reported structure for 4-bromo-3′-methylchalcone.

scholarly journals Noncovalent Interactions between 1,3,5-Trifluoro-2,4,6-triiodobenzene and a Series of 1,10-Phenanthroline Derivatives: A Combined Theoretical and Experimental Study

Crystals ◽  
2019 ◽  
Vol 9 (3) ◽  
pp. 140 ◽  
Author(s):  
Yu Zhang ◽  
Jian-Ge Wang ◽  
Weizhou Wang
Keyword(s):  
Crystal Structure ◽  
Crystal Structures ◽  
Quantum Chemical ◽  
Halogen Bond ◽  
Noncovalent Interactions ◽  
Stacking Interactions ◽  
Halogen Bonds ◽  
Π Stacking ◽  
Π Stacking Interaction ◽  
Structural Competition

How many strong C−I⋯N halogen bonds can one 1,3,5-trifluoro-2,4,6-triiodobenzene molecule form in a crystal structure? To answer this question, we investigated in detail the noncovalent interactions between 1,3,5-trifluoro-2,4,6-triiodobenzene and a series of 1,10-phenanthroline derivatives by employing a combined theoretical and experimental method. The results of the quantum chemical calculations and crystallographic experiments clearly show that there is a structural competition between a C−I⋯N halogen bond and π⋯π stacking interaction. For example, when there are much stronger π⋯π stacking interactions between two 1,10-phenanthroline derivative molecules or between two 1,3,5-trifluoro-2,4,6-triiodobenzene molecules in the crystal structures, then one 1,3,5-trifluoro-2,4,6-triiodobenzene molecule forms only one C−I⋯N halogen bond with one 1,10-phenanthroline derivative molecule. Another example is when π⋯π stacking interactions in the crystal structures are not much stronger, one 1,3,5-trifluoro-2,4,6-triiodobenzene molecule can form two C−I⋯N halogen bonds with two 1,10-phenanthroline derivative molecules.

Crystal structures of 7-azaindole, an unusual hydrogen-bonded tetramer, and of two of its methylmercury(II) complexes

1990 ◽  
Vol 68 (1) ◽  
pp. 193-201 ◽  
Author(s):  
Pascal Dufour ◽  
Yves Dartiguenave ◽  
Michèle Dartiguenave ◽  
Nathalie Dufour ◽  
Anne-Marie Lebuis ◽  
...  
Keyword(s):  
Crystal Structure ◽  
Nitrogen Atom ◽  
Hydrogen Bonds ◽  
Crystal Structures ◽  
Membered Ring ◽  
Pyridine Nitrogen Atom ◽  
Nitrate Ions ◽  
Pyridine Nitrogen ◽  
Independent Molecules ◽  
Hydrogen Bonded

Crystals of 7-azaindole ([Formula: see text], a = 11.312(4), b = 14.960(6), c = 15.509(5) Å, α = 102.86(3), β = 108.78(3), γ = 90.71(3)°, Z = 16, R = 0.052) contain tetrameric units of approximate S4 symmetry, in which the molecules are associated by means of four complementary N—H … N hydrogen bonds. [CH3Hg(7-azaindole)]NO3 ([Formula: see text], a = 7.818(3), b = 7.884(3), c = 9.135(4) Å, α = 97.89(3), β = 109.13(3), γ = 103.28(3)°, Z = 2, R = 0.039) contains well-separated nitrate ions and complex cations in which the methylmercury group is linearly bonded to the pyridine nitrogen atom, whereas the five-membered ring remains protonated. In the neutral [CH3Hg(azaindolate)] complex ([Formula: see text], a = 10.926(10), b = 11.333(8), c = 11.647(10) Å, α = 92.13(8), β = 104.83(9), γ = 111.86(7)°, Z = 6, R = 0.048), methylmercury groups have substituted the N—H proton in the five-membered ring for the three symmetry-independent molecules. Intermolecular secondary Hg … N bonds are found with pyridine nitrogens. Keywords: azaindole, methylmercury, crystal structure.

scholarly journals 1,3,5-Trifluoro-2,4,6-triiodobenzene–piperazine (2/1)

IUCrData ◽  
2021 ◽  
Vol 6 (10) ◽  
Author(s):  
Christelle Hajjar ◽  
Jeffrey S. Ovens ◽  
David L. Bryce
Keyword(s):  
Crystal Structure ◽  
Nitrogen Atom ◽  
Bond Angle ◽  
Halogen Bond ◽  
Covalent Bond ◽  
Halogen Bonding ◽  
The Other ◽  
Linear Interaction ◽  
Compound C ◽  
Van Der Waals Radii

The single-crystal structure of the title compound, C4H10N2·2C6F3I3, features a moderately strong halogen bond between one of the three crystallographically distinct iodine atoms and the nitrogen atom. The iodine–nitrogen distance is 2.820 (3) Å, corresponding to 80% of the sum of their van der Waals radii. The C—I...N halogen bond angle is 178.0 (1)°, consistent with the linear interaction of nitrogen via a σ-hole opposite the carbon–iodine covalent bond. The other two iodine atoms do not engage in halogen bonding. Some weak C—H...F and —H...I interactions are also observed. The complete piperazine molecule is generated by symmetry.

scholarly journals Crystal structures of three functionalized chalcones: 4′-dimethylamino-3-nitrochalcone, 3-dimethylamino-3′-nitrochalcone and 3′-nitrochalcone

2020 ◽  
Vol 76 (10) ◽  
pp. 1599-1604
Author(s):  
Charlie L. Hall ◽  
Victoria Hamilton ◽  
Jason Potticary ◽  
Matthew E. Cremeens ◽  
Natalie E. Pridmore ◽  
...  
Keyword(s):  
Crystal Structure ◽  
Hydrogen Bonding ◽  
Crystal Structures ◽  
Functional Groups ◽  
Organic Molecules ◽  
Two Dimensional ◽  
Large Dataset ◽  
Acta Cryst ◽  
Small Organic Molecules ◽  
Hydrogen Bonding Interactions

The structure of three functionalized chalcones (1,3-diarylprop-2-en-1-ones), containing combinations of nitro and dimethylamino functional groups, are presented, namely, 1-[4-(dimethylamino)phenyl]-3-(3-nitrophenyl)prop-2-en-1-one, C17H16N2O3, Gp8m, 3-[3-(dimethylamino)phenyl]-1-(3-nitrophenyl)prop-2-en-1-one, C17H16N2O3, Hm7m and 1-(3-nitrophenyl)-3-phenylprop-2-en-1-one, C15H11NO3, Hm1-. Each of the molecules contains bonding motifs seen in previously solved crystal structures of functionalized chalcones, adding to the large dataset available for these small organic molecules. The structures of all three of the title compounds contain similar bonding motifs, resulting in two-dimensional planes of molecules formed via C—H...O hydrogen-bonding interactions involving the nitro- and ketone groups. The structure of Hm1- is very similar to the crystal structure of a previously solved isomer [Jing (2009). Acta Cryst. E65, o2510].

Kristallstrukturen von Me2Si[N(SiMe3)2]2 und [Me2Si(NPh)(NHPh)Li·OEt2]2 / Crystal Structures of Me2Si[N(SiMe3)2]2 and [Me2Si(NPh)(NHPh)Li·OEt2]2

1998 ◽  
Vol 53 (9) ◽  
pp. 977-980 ◽  
Author(s):  
Andreas Mommertz ◽  
Gertraud Geiseier ◽  
Klaus Harms ◽  
Kurt Dehnicke
Keyword(s):  
Hydrogen Atom ◽  
Nitrogen Atom ◽  
Crystal Structures ◽  
Space Group ◽  
Bond Lengths

Abstract The crystal structures of the title compounds are reported. Me2Si[N(SiMe3)2]2: Space group Pbcn, Z = 4, lattice dimensions at 213 K: a = 1487.8(1), b = 1299.4(1), c = 1259.7(1) pm. The compound forms monomeric molecules with crystallographic C2 symmetry and Si-N bond lengths of 177.9(3), 171.6(3) and 175,2(3) pm. [Me2Si(NPh)(NHPh)Li·OEt2]2: Space group P21/n, Z = 2, lattice dimensions at 190 K: a = 1082.7(3), b = 1038.8(2), c = 1641.3(4) pm, β = 91.350(3)°. The compound forms centrosymmetric dimeric molecules in which the lithium atoms are members of a Li2N2 ring with Li-N bond lengths of 206.6(2) and 213.5(2) pm. The hydrogen atom at the nitrogen atom of the HNPh- group is not involved in hydrogen bridging bonds.

Crystal structures, Hirshfeld surface analysis and Pixel energy calculations of three trifluoromethylquinoline derivatives: further analyses of fluorine close contacts in trifluoromethylated derivatives

2019 ◽  
Vol 74 (11-12) ◽  
pp. 791-810
Author(s):  
Lígia R. Gomes ◽  
Emerson T. da Silva ◽  
Marcus V.N. de Souza ◽  
James L. Wardell ◽  
John N. Low
Keyword(s):  
Biological Activity ◽  
Crystal Structures ◽  
Fluorine Atom ◽  
Hirshfeld Surface ◽  
Energy Calculations ◽  
Hirshfeld Analysis ◽  
Structure Determinations ◽  
Biological Target ◽  
Close Contacts

AbstractAs many studies have revealed, the introduction of a CF3 group into an organic compound can result in significant enhancement of biological activity. Factors which lead to this enhancement are thus of great interest. To investigate further this area, we have looked at the ability of fluorine to form close contacts with various atoms in organic compounds, e.g. F⋯F, F⋯O/O⋯F, F⋯C/C⋯F, H⋯F/F⋯H, and F⋯N/N⋯F, as indicated from crystal structure determinations and Hirshfeld analysis studies on trifluoromethylated compounds. Herein we first report the crystal structures, Hirshfeld surface analyses (HSA), and Pixel energy calculations of three trifluoromethylated quinoline derivatives, namely 2-(trifluoromethyl)quinolin-4-ol, 1, 4-ethoxy-2-(trifluoromethyl)quinoline, 2, and N1-(2,8-bis(trifluoromethyl)quinolin-4-yl)ethane-1,2-diamine, 3. Of particular interest is the determination of the various fluorine⋯atom close contacts. The total percentages of fluorine⋯atom close contacts in compounds 1–3 were determined to be high at 47, 41.2 and 60.7%, respectively. As relatively few HSA studies on trifluoromethylated compounds have reported the percentages of individual atom⋯atom close contacts, we have also determined the percentages of atom⋯atom close contacts for 20 more trifluoromethylated compounds: the range of total fluorine⋯atom close contacts for these compounds was 20–60%. While these data are based on connections between similar molecules in a crystalline state, they also clearly suggest that a compound containing CF3 group(s) has the potential to make extensive intermolecular connections/close contacts with organic material. Thus a possible factor for the enhanced biological activity of a compound bearing CF3 group(s) could be the propensity of the CF3 group to form many close contacts, thereby aiding binding or interaction with a biological target.

scholarly journals Crystal structure and Hirshfeld analysis of 2-(5-bromothiophen-2-yl)acetonitrile

2018 ◽  
Vol 74 (2) ◽  
pp. 189-192 ◽  
Author(s):  
Ted M. Pappenfus ◽  
Tiana L. Wood ◽  
Joseph L. Morey ◽  
Wyatt D. Wilcox ◽  
Daron E. Janzen
Keyword(s):  
Crystal Structure ◽  
Title Compound ◽  
Nitrile Group ◽  
Type I ◽  
Asymmetric Unit ◽  
Space Group ◽  
Π Interactions ◽  
Compound C ◽  
Hirshfeld Analysis

The title compound, C6H4BrNS, crystallizes in the space group P21/n with one complete molecule in the asymmetric unit. The non-H atoms are nearly planar (r.m.s for non-H atoms = 0.071 Å), with the nitrile group oriented antiperiplanar with respect to the thiophene S atom. Intermolecular Type I centrosymmetric Br...Br halogen interactions are present at a distance of 3.582 (1) Å and with a C—Br...Br angle of 140.7 (1)°. Additional weaker C—H...N, C—H...S, and S...π interactions are also present. A Hirshfeld analysis indicates Br...Br interactions comprise only 1.9% of all the interatomic contacts.

scholarly journals Crystal structures of 2-[3,5-bis(bromomethyl)-2,4,6-triethylbenzyl]isoindoline-1,3-dione and 2-{5-(bromomethyl)-3-[(1,3-dioxoisoindolin-2-yl)methyl]-2,4,6-triethylbenzyl}isoindoline-1,3-dione

2021 ◽  
Vol 77 (9) ◽  
Author(s):  
Manuel Stapf ◽  
Betty Leibiger ◽  
Anke Schwarzer ◽  
Monika Mazik
Keyword(s):  
Crystal Structure ◽  
Hydrogen Bonding ◽  
Hydrogen Bonds ◽  
Crystal Structures ◽  
Molecular Conformation ◽  
Halogen Bond ◽  
Asymmetric Unit ◽  
Space Group ◽  
Π Interactions ◽  
Hydrogen Bonding Interactions

The title compounds, C23H25Br2NO2 (1) and C31H29BrN2O4 (2), crystallize in the space group P21/n with two (1-A and 1-B) and one molecules, respectively, in the asymmetric unit of the cell. The molecular conformation of these compounds is stabilized by intramolecular C—H...O hydrogen bonds and C—H...N or C—H...π interactions. The crystal structure of 1 features a relatively strong Br...O=C halogen bond, which is not observed in the case of 2. Both crystal structures are characterized by the presence of C—H...Br hydrogen bonds and numerous intermolecular C—H...O hydrogen-bonding interactions.

scholarly journals Halogen bonds in some dihalogenated phenols: applications to crystal engineering

IUCrJ ◽  
2013 ◽  
Vol 1 (1) ◽  
pp. 49-60 ◽  
Author(s):  
Arijit Mukherjee ◽  
Gautam R. Desiraju
Keyword(s):  
Crystal Structure ◽  
Crystal Structures ◽  
Crystal Engineering ◽  
Structure Prediction ◽  
Variable Temperature ◽  
Type I ◽  
Type Ii ◽  
Halogen Bonds ◽  
Space Groups ◽  
Starting Model

3,4-Dichlorophenol (1) crystallizes in the tetragonal space groupI41/awith a short axis of 3.7926 (9) Å. The structure is unique in that both type I and type II Cl...Cl interactions are present, these contact types being distinguished by the angle ranges of the respective C—Cl...Cl angles. The present study shows that these two types of contacts are utterly different. The crystal structures of 4-bromo-3-chlorophenol (2) and 3-bromo-4-chlorophenol (3) have been determined. The crystal structure of (2) is isomorphous to that of (1) with the Br atom in the 4-position participating in a type II interaction. However, the monoclinicP21/cpacking of compound (3) is different; while the structure still has O—H...O hydrogen bonds, the tetramer O—H...O synthon seen in (1) and (2) is not seen. Rather than a type I Br...Br interaction which would have been mandated if (3) were isomorphous to (1) and (2), Br forms a Br...O contact wherein its electrophilic character is clearly evident. Crystal structures of the related compounds 4-chloro-3-iodophenol (4) and 3,5-dibromophenol (5) were also determined. A computational survey of the structural landscape was undertaken for (1), (2) and (3), using a crystal structure prediction protocol in space groupsP21/candI41/awith the COMPASS26 force field. While both tetragonal and monoclinic structures are energetically reasonable for all compounds, the fact that (3) takes the latter structure indicates that Br prefers type II over type I contacts. In order to differentiate further between type I and type II halogen contacts, which being chemically distinct are expected to have different distance fall-off properties, a variable-temperature crystallography study was performed on compounds (1), (2) and (4). Length variations with temperature are greater for type II contacts compared with type I. The type II Br...Br interaction in (2) is stronger than the corresponding type II Cl...Cl interaction in (1), leading to elastic bending of the former upon application of mechanical stress, which contrasts with the plastic deformation of (1). The observation of elastic deformation in (2) is noteworthy; in that it finds an explanation based on the strengths of the respective halogen bonds, it could also be taken as a good starting model for future property design. Cl/Br isostructurality is studied with the Cambridge Structural Database and it is indicated that this isostructurality is based on shape and size similarity of Cl and Br, rather than arising from any chemical resemblance.

scholarly journals Tautomeric Equilibrium of an Asymmetric β-Diketone in Halogen-Bonded Cocrystals with Perfluorinated Iodobenzenes

Crystals ◽  
2021 ◽  
Vol 11 (6) ◽  
pp. 699
Author(s):  
Valentina Martinez ◽  
Nikola Bedeković ◽  
Vladimir Stilinović ◽  
Dominik Cinčić
Keyword(s):  
Solid State ◽  
Hydrogen Atom ◽  
Crystal Structures ◽  
Crystal Packing ◽  
Halogen Bond ◽  
Tautomeric Equilibrium ◽  
Hydroxyl Group ◽  
Halogen Bonds ◽  
Pyridyl Nitrogen

In order to study the effect of halogen bond on tautomerism in β-diketones in the solid-state, we have prepared a series of cocrystals derived from an asymmetric β-diketone, benzoyl-4-pyridoylmethane (b4pm), as halogen bond acceptor and perfluorinated iodobenzenes: iodopentaflourobenzene (ipfb), 1,2-, 1,3- and 1,4-diiodotetraflorobenzene (12tfib, 13tfib and 14tfib) and 1,3,5-triiodo-2,4,6-trifluorobenzene (135titfb). All five cocrystals are assembled by I···N halogen bonds involving pyridyl nitrogen and iodoperfluorobenzene iodine resulting in 1:1 (four compounds) or 1:2 (one compound) cocrystal stoichiometry. Tautomer of b4pm in which hydrogen atom is adjacent to the pyridyl fragment was found to be more stable in vacuo than tautomer with a benzoyl hydroxyl group. This tautomer is also found to be dominant in the majority of crystal structures, somewhat more abundantly in crystal structures of cocrystals in which additional I···O halogen bond with the benzoyl oxygen has been established. Attempts have also been made to prepare an equivalent series of cocrystals using a closely related asymmetric β-diketone, benzoyl-3-pyridoylmethane (b3pm); however, all attempts were unsuccessful, which is attributed to more effective crystal packing of b3pm isomer compared to b4pm, which reduced the probability of cocrystal formation.

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